Suspension upgrade recommendations

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Animal Lawyer

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I understand that what I am asking is mainly subjective, but I respect the opinions from this board

1973 Vert, w/ 1970 351c (approx 375hp) w/air & ps, competition suspension and f&r sway bars and subframe connectors. Newly rebuily close ratio steering box

My questions

Rear leaf springs - 138 or 153 lb springs? While I prefer a stiffer ride, it is a street car and I don't want it to be bone jarring.

I prefer a more level to nose down stance, should I get the +1" springs or go with the longer shackles? (I can order the stock height from NPD at $440 shipped or the +1" direct from Eaton Detroit for $668, so unless there is a major advantage to the +1" springs, I prefer the $228 savings)

Urethane bushings & HD shackles or stay OE?

Front is there really a major advantage in the Opentracker blueprinted upper arms & roller perchs over stock for a non-lowered street car?

Is there sufficient benefit to justify the $425 cost for the adjustable strut rods?

As the Opentracker roller idler arms are no longer available, is there a suggestion as to a replacement?

My front end is tight but I seem to have a bit of wander, trying to tighten up everything and give it a more precise ride. If it were a europen I would go with coilovers all around, I am unsure what is best and most cost effective for a street car in this case.

Thanks

Rich
 
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If the suspension is tight and you have a bit of wander check your steering box, your rag joint, and your steering column. Sometimes one of them has play, or they all have a bit of play and it just compounds itself. West Coast Classic Cougars did a really good video on this:
 

machcrazy

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351 Cleveland 4v
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I understand that what I am asking is mainly subjective, but I respect the opinions from this board

1973 Vert, w/ 1970 351c (approx 375hp) w/air & ps, competition suspension and f&r sway bars and subframe connectors. Newly rebuily close ratio steering box

My questions

Rear leaf springs - 138 or 153 lb springs? While I prefer a stiffer ride, it is a street car and I don't want it to be bone jarring.

I prefer a more level to nose down stance, should I get the +1" springs or go with the longer shackles? (I can order the stock height from NPD at $440 shipped or the +1" direct from Eaton Detroit for $668, so unless there is a major advantage to the +1" springs, I prefer the $228 savings)

Urethane bushings & HD shackles or stay OE?

Front is there really a major advantage in the Opentracker blueprinted upper arms & roller perchs over stock for a non-lowered street car?

Is there sufficient benefit to justify the $425 cost for the adjustable strut rods?

As the Opentracker roller idler arms are no longer available, is there a suggestion as to a replacement?

My front end is tight but I seem to have a bit of wander, trying to tighten up everything and give it a more precise ride. If it were a europen I would go with coilovers all around, I am unsure what is best and most cost effective for a street car in this case.

Thanks

Rich
I went with new springs but 1 more leaf than stock. It leveled out and had a really nice ride. Originally they sat a little lower in the rear. I hate shackles and don't like seeing them below the body.
 

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As you say it is subjective depending also on how you use your car. I spent a lot of effort in the front suspension but I also run AutoX and track so I won't go in that direction because most of these mods are not needed for street use. However, of all the mods I have done, the one that I consider made the best improvement was going with Mike Maier's 4.5 leaf springs and Bilstein shocks. The improvement in traction and suspension feel was enormous to say the least. His leaf springs are expensive but you pay what you get for. I have only used these 4.5 leaf springs so I can't compare to others. The rear will feel firm but not overly stiff and you will eliminate wheel hop without the use of traction bars.
One thing I have to say about coilovers in the front is that by themselves they will not give you a performance advantage if you were using the same coil rating. However, it allows you to easily change your ride height, which is a big plus, but not a necessity for most.
As mentioned above checking any slop in the steering components makes a huge difference. Sending the steering box to a reputable rebuilder and changing the internal valving to a more "stiff" feeling helps a ton.
I have mix feelings about the strut rod upgrade. That will entirely depend on how you drive your car. The clevis type of strut rod takes a lot of the unwanted flex that comes from the strut rod bushings and the adjustable feature makes adjusting caster a breeze.
 

pepperdog

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I understand that what I am asking is mainly subjective, but I respect the opinions from this board

1973 Vert, w/ 1970 351c (approx 375hp) w/air & ps, competition suspension and f&r sway bars and subframe connectors. Newly rebuily close ratio steering box

My questions

Rear leaf springs - 138 or 153 lb springs? While I prefer a stiffer ride, it is a street car and I don't want it to be bone jarring.

I prefer a more level to nose down stance, should I get the +1" springs or go with the longer shackles? (I can order the stock height from NPD at $440 shipped or the +1" direct from Eaton Detroit for $668, so unless there is a major advantage to the +1" springs, I prefer the $228 savings)

Urethane bushings & HD shackles or stay OE?

Front is there really a major advantage in the Opentracker blueprinted upper arms & roller perchs over stock for a non-lowered street car?

Is there sufficient benefit to justify the $425 cost for the adjustable strut rods?

As the Opentracker roller idler arms are no longer available, is there a suggestion as to a replacement?

My front end is tight but I seem to have a bit of wander, trying to tighten up everything and give it a more precise ride. If it were a europen I would go with coilovers all around, I am unsure what is best and most cost effective for a street car in this case.

Thanks

Rich
Hi Rich, mine rides and handles very well with only minor tweaks. People often ask how i have set up the suspension and are surprised how little i have done. In the front I have 2" lowering sport springs from a local suspension shop, standard sway bar with urethane bushes, new upper and lower control arms, Bilstein shocks purchased from Road and Track, on the rear Scott Drake reverse eye 2" lowering springs, urethane bushes in standard sway bar, Bilstein shocks, and the biggest improvement was the welded in subframe connectors. I also had to put in some traction rods to stop my horrendous axle hop if I ever decided to get under it. The traction rods were modified Shelby type and after playing around with the mounting height of the ubolt location I have no suspension bind at all and a small 15mm spacer between both plates. Anyways it works for me.hoist must.jpg
 

Sheriff41

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Hi Rich, mine rides and handles very well with only minor tweaks. People often ask how i have set up the suspension and are surprised how little i have done. In the front I have 2" lowering sport springs from a local suspension shop, standard sway bar with urethane bushes, new upper and lower control arms, Bilstein shocks purchased from Road and Track, on the rear Scott Drake reverse eye 2" lowering springs, urethane bushes in standard sway bar, Bilstein shocks, and the biggest improvement was the welded in subframe connectors. I also had to put in some traction rods to stop my horrendous axle hop if I ever decided to get under it. The traction rods were modified Shelby type and after playing around with the mounting height of the ubolt location I have no suspension bind at all and a small 15mm spacer between both plates. Anyways it works for me.View attachment 62617
Great looking Mach 1 right there!
 
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Here’s picture of Calvert S640-34 Split Mono Leaf, 64-73 Mustang (4-1/8”) with CLV-6401 Traction Bars.
The ride height is about stock, haven’t put them to test yet. They seem just fine around town and on highway.
 

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Joined
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Hi Rich, mine rides and handles very well with only minor tweaks. People often ask how i have set up the suspension and are surprised how little i have done. In the front I have 2" lowering sport springs from a local suspension shop, standard sway bar with urethane bushes, new upper and lower control arms, Bilstein shocks purchased from Road and Track, on the rear Scott Drake reverse eye 2" lowering springs, urethane bushes in standard sway bar, Bilstein shocks, and the biggest improvement was the welded in subframe connectors. I also had to put in some traction rods to stop my horrendous axle hop if I ever decided to get under it. The traction rods were modified Shelby type and after playing around with the mounting height of the ubolt location I have no suspension bind at all and a small 15mm spacer between both plates. Anyways it works for me.View attachment 62617
Nice looking car! As a curiosity, could you measure your ride height from the ground to the center of the fenders on the front and rear?
 

pepperdog

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Nice looking car! As a curiosity, could you measure your ride height from the ground to the center of the fenders on the front and rear?
sure just noticed your post will do it this afternoon, as a side note i run 18 inch wheels i think 8 front and 9 rear with 245 50 and 255 50 Nitto Invo tyres which probably helps as well
 

pepperdog

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Nice looking car! As a curiosity, could you measure your ride height from the ground to the center of the fenders on the front and rear?
from the ground to the top centre of the wheel arches - front 635mm rear 655mm. on the road it appears as thought the rear is lower, I've never measured it before it is an optical illusion the front is definitely lower
 

DaveMT

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1973 Mach-1 Sportsroof (1970, 351C-4V M-Code Motor, 4-Speed Toploader)
After tiring of seeing the rear end of my 73 Mach-1 drooping so much from worn out leaf springs, I installed a set of Scott Drake (#C5ZZ-5560-HD) 5-leaf rear springs which I purchased from Summit Racing. According to the specs on Summit they have a 195 Lb. spring rate and I love them (see attached pic). I think my Mach-1 has a much better stance now and it still rides quite nicely and it does not have a truck-like ride at all. I also installed new (standard replacement) shackles and hardware but had to install slightly longer U-bolts to accommodate the extra leaf. I had somehwat of a difficult time finding them until someone on one of these Mustang forums pointed out exactly what I needed which was Ford #D0ZZ-5705-A. I found a set of 4 of them at National Parts Depot (npdlink.com) and they worked great.
 

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machcrazy

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351 Cleveland 4v
Automatic overdrive transmission
I did the same...5 leaf springs, ride is good and has a better stance. I didn't stagger wheels though.
 

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1972 Mustang Convertible, 351 C2V, 3 Speed Manual Transmission, Decor Group, Color Keyed Racing Mirrors. 6C Medium Goldenrod, White Knit Vinyl Bucket
Hi Rich, mine rides and handles very well with only minor tweaks. People often ask how i have set up the suspension and are surprised how little i have done. In the front I have 2" lowering sport springs from a local suspension shop, standard sway bar with urethane bushes, new upper and lower control arms, Bilstein shocks purchased from Road and Track, on the rear Scott Drake reverse eye 2" lowering springs, urethane bushes in standard sway bar, Bilstein shocks, and the biggest improvement was the welded in subframe connectors. I also had to put in some traction rods to stop my horrendous axle hop if I ever decided to get under it. The traction rods were modified Shelby type and after playing around with the mounting height of the ubolt location I have no suspension bind at all and a small 15mm spacer between both plates. Anyways it works for me.View attachment 62617
Beautiful Mach 1 !! What size are your tires and wheels? I really like the look !! The wheels look sort of like Magnum 500 replicas, may I ask what brand they are ?
 
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Stock 1973 Mustang Convertible with a 351C 2v and C6
Modified 1970 Mach 1 M-Code with a 351C 4v Manual

I understand that what I am asking is mainly subjective, but I respect the opinions from this board

1973 Vert, w/ 1970 351c (approx 375hp) w/air & ps, competition suspension and f&r sway bars and subframe connectors. Newly rebuily close ratio steering box

My questions

Rear leaf springs - 138 or 153 lb springs? While I prefer a stiffer ride, it is a street car and I don't want it to be bone jarring.

I prefer a more level to nose down stance, should I get the +1" springs or go with the longer shackles? (I can order the stock height from NPD at $440 shipped or the +1" direct from Eaton Detroit for $668, so unless there is a major advantage to the +1" springs, I prefer the $228 savings)

Urethane bushings & HD shackles or stay OE?

Front is there really a major advantage in the Opentracker blueprinted upper arms & roller perchs over stock for a non-lowered street car?

Is there sufficient benefit to justify the $425 cost for the adjustable strut rods?

As the Opentracker roller idler arms are no longer available, is there a suggestion as to a replacement?

My front end is tight but I seem to have a bit of wander, trying to tighten up everything and give it a more precise ride. If it were a europen I would go with coilovers all around, I am unsure what is best and most cost effective for a street car in this case.

Thanks

Rich
I have a 73 vert which is factory with stock suspension. The ride height is a bit high, but that's the way it was back then. My tires do a good job at filling the wheel wells, so the height looks fine. I used rubber bushing.

I also have a 70 Mach with Global West front suspension with the 1" Shelby drop on the upper arm control, and Eaton stock ride height 138lbs 4 leaf rear leaf springs that I ordered from NPD. I added aftermarket 4-wheel disc brakes.

Not much to say about the rear suspension, I installed factory height 4 leaf 138 lbs competition suspension springs. I added an aftermarket 1" sway bar and Cal Trac traction Bars. The rear ride is not harsh at all and the CalcTracs keep the tires on the pavement. The ride height is surprisingly a bit lower than I expected, but I am very happy with it.

The 70 Global West front suspension is really nice. I installed Global West Plus 3 front suspension. The Global West Tubular Upper Control Arms # MNR-733 and lower control arms, along with their adjustable strut rods. Also used their Eccentric Loc-Outs and Big Block Coils constant rate coils springs. Again, the ride height up front is surprisingly a bit lower than I expected, but I am very happy with it. Keep in mind that lowering the ride height too much can cause driveline angle issues, which will need to be corrected to avoid driveshaft and U joint issues, not to mention potentially noise and vibration.
if not addressed.

The Shelby Drop changes the front suspension geometry to improve handling. Although I think it does lower it some. It was one of many mods recommended for track and street in the Boss302 Chassis Modification book. There are three stages of mods from weekend track racing to All-Out racing depending on your intentions. Below is the diagram for it. Global West provides a 1" drop steel template for drilling the (1" drop) holes and the alignment specs for your mechanic.

With their suspension, Global West claims to eliminate alignment/adjustment limitations: Caster on 1967-73 Mustangs is adjusted by moving the lower control arm forward via the strut rod. The strut rod is threaded at one end where the rubber bushings reside. By loosening and tightening the jam nuts you can pull the lower arm forward gaining more caster. The real limitation on how much caster you can get is restricted by the rim and tire size combination you are using. The larger sizes limit how far you can move the lower arm forward because the tire runs into the lower portion of the front fender when the wheel is turned. If this occurs, you will have to reduce caster, which is not the best answer. Global West Plus 3 upper arms have 3 degrees of positive caster built into them. This will eliminate the need to pull the lower arm so far forward in order to get the desired alignment. The arm provides an additional positive caster by moving the upper ball joint back towards the rear of the car. So you have more caster adjustability. Keep in mind this changes the alignment specs, so stock specs are not applicable anymore.

I have a good friend with a 71 Mach 1 and he installed the same Global West Suspension and his Mach handles great. He also installed 1" lowering springs instead of ride height.

Finally, expect your new suspension will make the car sit higher than your old, but it will settle down some over the first 6 months or so.

Ride Hieght Comparision.jpg
 

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Duncan Mach72

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351C 4V, 4 speed
Alum flywheel
McLeod clutch
Torque biasing diff, 3.5:1
31 spline Strange SS axles
Dual 2.5" exhaust
I have a 73 vert which is factory with stock suspension. The ride height is a bit high, but that's the way it was back then. My tires do a good job at filling the wheel wells, so the height looks fine. I used rubber bushing.

I also have a 70 Mach with Global West front suspension with the 1" Shelby drop on the upper arm control, and Eaton stock ride height 138lbs 4 leaf rear leaf springs that I ordered from NPD. I added aftermarket 4-wheel disc brakes.

Not much to say about the rear suspension, I installed factory height 4 leaf 138 lbs competition suspension springs. I added an aftermarket 1" sway bar and Cal Trac traction Bars. The rear ride is not harsh at all and the CalcTracs keep the tires on the pavement. The ride height is surprisingly a bit lower than I expected, but I am very happy with it.

The 70 Global West front suspension is really nice. I installed Global West Plus 3 front suspension. The Global West Tubular Upper Control Arms # MNR-733 and lower control arms, along with their adjustable strut rods. Also used their Eccentric Loc-Outs and Big Block Coils constant rate coils springs. Again, the ride height up front is surprisingly a bit lower than I expected, but I am very happy with it. Keep in mind that lowering the ride height too much can cause driveline angle issues, which will need to be corrected to avoid driveshaft and U joint issues, not to mention potentially noise and vibration.
if not addressed.

The Shelby Drop changes the front suspension geometry to improve handling. Although I think it does lower it some. It was one of many mods recommended for track and street in the Boss302 Chassis Modification book. There are three stages of mods from weekend track racing to All-Out racing depending on your intentions. Below is the diagram for it. Global West provides a 1" drop steel template for drilling the (1" drop) holes and the alignment specs for your mechanic.

With their suspension, Global West claims to eliminate alignment/adjustment limitations: Caster on 1967-73 Mustangs is adjusted by moving the lower control arm forward via the strut rod. The strut rod is threaded at one end where the rubber bushings reside. By loosening and tightening the jam nuts you can pull the lower arm forward gaining more caster. The real limitation on how much caster you can get is restricted by the rim and tire size combination you are using. The larger sizes limit how far you can move the lower arm forward because the tire runs into the lower portion of the front fender when the wheel is turned. If this occurs, you will have to reduce caster, which is not the best answer. Global West Plus 3 upper arms have 3 degrees of positive caster built into them. This will eliminate the need to pull the lower arm so far forward in order to get the desired alignment. The arm provides an additional positive caster by moving the upper ball joint back towards the rear of the car. So you have more caster adjustability. Keep in mind this changes the alignment specs, so stock specs are not applicable anymore.

I have a good friend with a 71 Mach 1 and he installed the same Global West Suspension and his Mach handles great. He also installed 1" lowering springs instead of ride height.

Finally, expect your new suspension will make the car sit higher than your old, but it will settle down some over the first 6 months or so.

View attachment 64407
The Shelby drop is not essential on 71-73 cars like it is on 65-70. Ford did actually fix the suspension geometry for us in 71 so there is no camber gain or loss on suspension travel. I didn't know this, dropped my arms 1 3/4", ended up with a lower front end, much less suspension travel, awesome front end grip in turns but bad bump steer on braking. I have gone back to stock at the moment.
 
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Correct. Our cars don't need the Shelby drop. A lot of these suspensions are mainly sold for pre 1971 but the instructions are not clear about the 71-73 not needing the Shelby drop. An alternative to Global West is Mike Maier's MOD 1 suspension with coil overs.
 

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