Need to replace front and rear springs

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AcesArneson

73' Vert with NACA Ram Air
7173 Mustang Supporter Member
Joined
Aug 17, 2019
Messages
369
Reaction score
237
Location
Fort McMurray, Alberta
My Car
'73 Vert with 4R70W
351C Ram Air 2V 441 hp @ 6000 RPM
SEFI EEC-V (2004)
9" trac-loc limited slip 3.5:1
P-Zero 265/35ZR-19's front 305/30ZR-19's rear
Finally getting to that stage of the restoration where I can determine accurately the weight reductions I have achieved for picking out springs.
At the start of my project I foolishly picked out springs that I thought would stiffen up the boat-like cruising just enough to enjoy the ride. I purchased the 5 leaf rear springs and the big block progressive coil springs, even though I have a 2V Cleveland I thought the progressives for a big block would stiffen the ride just enough to enjoy cornering.
The problem is that while rebuilding the engine I started shaving pounds off the old girl and now those BB springs will shake the crap out of me when I get her on the road. As near as I can figure without actually hitting the scale (she is still in pieces in the garage), I believe I have shaved 170 lbs off the front end of the car.
-2V stock heads 60 lbs, replacement Edelbrock aluminum heads 35 lbs = total reduction ~ 50 lbs between both heads.
-2V stock intake 42 lbs, replacement Weiand intake 22 lbs = total reduction of 20 lbs.
-stock hood 100 lbs, replacement NACA hood 50 lbs = total reduction 50 lbs.
-stock front bumper 74 lbs plus brackets tops 100lbs, swap to 72 style (paintable) all in is less than 50 lbs = total reduction of 50 lbs.

I have also swapped the upper control arms for Global West +3's, swapped brakes to S550 package, upgraded sway bars to 1-1/8" up front and 7/8" in the rear, added the Global West frame connectors, changed rear gears to 3.5:1 limited slip, and ordered a Monte Carlo bar to brace the towers.

I bought the recommended Bilstein gas shocks, so now what do I do about these springs?
 
Do you have the manufacturer and part # for the front springs?
I should also mention, I am not looking to drop the car at all yet. Digging through the instructions for the Global West UCA's I decided to go with the "non drop" version. I have read plenty of stories on here where guys say they fixed the issues with steering in 71 and the drop was not needed.

Front: C7ZZ-5310-BB-PR COIL SPRINGS 67/73 BIG BLOCK 1 PROGRESSIVE 460/600#
with COIL SPRING INSULATOR POLY URE 1/4in 1 65-73 PAIR

Rear: C5ZZ-5560-HD LEAF SPRING 65/73 5 LEAF 2

R056. BILSTEIN REAR SHOCKS –(1965-1973 1 MUSTANG)

R047 BILSTEIN FRONT SHOCKS –STREET VALVE 1 (71-73 MUSTANG PAIR)

I went with the 5 leaf because I hear a lot of chatter over wheel hop. My Vert does not have staggered shocks so I am a little concerned I might need traction bars but I also read somewhere that 5 leafs reduced wheel hop. One individual even says that if you clamp the front of each leaf the hop will be gone. Just not sure about the ride quality with the 5 leaf. Since I have them on the car already I think I will try those out but I am still pretty certain I made a mistake with the BB front springs.
 
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I have 5 leaf rear like you do. Got them to help with axle wrap like you mentioned. Now I think 4 leaf and cal tracks would have been better.

I have the global west 3 degree Shelby drop on mine with the rest opentracker racing. Using the stock small block springs.

351c with tfs heads, but added the weight of the supercharger.

I have a set of small block progressive springs that have 100 miles on them before I did the drop. Shipping would be expensive, but I have zero need for them. Looks like I paid $220 for them. I would sell for $100 plus shipping
 

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I have 5 leaf rear like you do. Got them to help with axle wrap like you mentioned. Now I think 4 leaf and cal tracks would have been better.

I have the global west 3 degree Shelby drop on mine with the rest opentracker racing. Using the stock small block springs.

351c with tfs heads, but added the weight of the supercharger.

I have a set of small block progressive springs that have 100 miles on them before I did the drop. Shipping would be expensive, but I have zero need for them. Looks like I paid $220 for them. I would sell for $100 plus shipping

I have 5 leaf rear like you do. Got them to help with axle wrap like you mentioned. Now I think 4 leaf and cal tracks would have been better.

I have the global west 3 degree Shelby drop on mine with the rest opentracker racing. Using the stock small block springs.

351c with tfs heads, but added the weight of the supercharger.

I have a set of small block progressive springs that have 100 miles on them before I did the drop. Shipping would be expensive, but I have zero need for them. Looks like I paid $220 for them. I would sell for $100 plus shipping
How do the 5 leaf handle wheel hop?
Thanks for the offer, where do you live?
 
If you have not yet ordered springs I suggest you call Easton Detroit Springs. The rep will ask a lot of questions about your car and how you want to use it. Then they will provide a solid, "take it to the bank," recommendation for springs (fron and rear). Their web site is at:

https://www.eatondetroitspring.com/

Their phone # is: (313) 963-3839
 
If you have not yet ordered springs I suggest you call Easton Detroit Springs. The rep will ask a lot of questions about your car and how you want to use it. Then they will provide a solid, "take it to the bank," recommendation for springs (fron and rear). Their web site is at:

https://www.eatondetroitspring.com/

Their phone # is: (313) 963-3839
Thanks again guys. appreciate all the great advice. I called Eaton and they suggested MC 3718's. This is the 'improved suspension' spring for small blocks without A/C. My 73 Vert' does have A/C but he suggested this one because of the other weight reductions on the front end. This spring will drop the suspension approximately 1" but I will boost it back up with a collar if the drop is too noticeable or I don't like it. Since my springs are 52 years old I might not even notice the difference.
Incidentally, I asked if I should consider a progressive spring (like the big block one I had already purchased but haven't tried out yet) and he said stay away from progressives, you want a Smooth transition through cornering. Has anyone had a good experience with progressive springs? I would love to hear how your experience is going.
 
The Holley website offers zero information on those front springs. You're probably just going to have to install them and then trim to suit your desired ride height. That's pretty much how it is going forward with so many part numbers being consolidated, unless you want to spring for Eaton parts. I've heard several times over the years to not use progressive springs on these cars.

I've never ridden in a 5 leaf equipped Mustang, but I can say the Camaros that friends put them in were "stiff" to be kind. The factory 138 lb/in Competition Suspension springs are a firm ride.
 
The Holley website offers zero information on those front springs. You're probably just going to have to install them and then trim to suit your desired ride height. That's pretty much how it is going forward with so many part numbers being consolidated, unless you want to spring for Eaton parts. I've heard several times over the years to not use progressive springs on these cars.

I've never ridden in a 5 leaf equipped Mustang, but I can say the Camaros that friends put them in were "stiff" to be kind. The factory 138 lb/in Competition Suspension springs are a firm ride.
Thanks, if I ever get this project finished I will reach back to this topic to finish it off. Pretty sure it's going to be too stiff on the back but I might as well try them out.
 
You have obviously made many improvements for both power and handling. My thought is to weigh each corner of the car, provided the weight info to Eaton, along with the improvements you’ve made so you can get an accurate recommendation. You need to determine what ride height you want and what you are willing to compromise between handling and ride quality. With all the info, Eaton can take the guesswork out of the equation and provide you with springs that meet your expectations.
 
If you have not yet ordered springs I suggest you call Easton Detroit Springs. The rep will ask a lot of questions about your car and how you want to use it. Then they will provide a solid, "take it to the bank," recommendation for springs (fron and rear). Their web site is at:

https://www.eatondetroitspring.com/

Their phone # is: (313) 963-3839
ABSOLUTELY!
You took the words out of my mouth so to speak.

As for shocks, I initially put KYB Gas-A-Just, but later switched to KYB Excel G, which are less harsh. I also have Addco 7/8" rear anti sway bar with a 1 1/8" front. My rear springs are Eaton Boss 351 @ 153 lbs spring rate, but the 138 lb would have been perfectly fine.
 
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ABSOLUTELY!
You took the words out of my mouth so to speak.

As for shocks, I initially put KYB Gas-A-Just, but later switched to KYB Excel G, which are less harsh. I also have Addco 7/8" rear anti sway bar with a 1 1/8" front. My rear springs are Eaton Boss 351 @ 153 lbs spring rate, but the 138 lb would have been perfectly fine.
Every once in a while my light bulb does burn pretty brightly. heh heh... I am very happy to be able help fellow enthusiasts, an honored to be in the midst of such knowledgable folks. It makes having these vintage pony cars all the more fun and exciting to own and tinker with.
 
You have obviously made many improvements for both power and handling. My thought is to weigh each corner of the car, provided the weight info to Eaton, along with the improvements you’ve made so you can get an accurate recommendation. You need to determine what ride height you want and what you are willing to compromise between handling and ride quality. With all the info, Eaton can take the guesswork out of the equation and provide you with springs that meet your expectations.
Thanks, I gave them a call and they recommended their small block (non-A/C) improved handling MC3718 springs. My car has A/C but their non-A/C springs are meant to provide improved handling with a lighter car. The spring rate for this spring is 362 lb. over a standard rate of 295 lb. so I will try the higher rated springs and see if that is the ride I am looking for.
I ordered standard height springs to go with the standard height Global West upper control arms with improved castor, which are said to drop your front end by almost an inch.
All of my weight reductions are balanced left to right but you raise a good question about getting the corner weights. I can't wait to get this thing together and see if the improvements give me a sportier handling feel without shaking my fillings loose.
 
ABSOLUTELY!
You took the words out of my mouth so to speak.

As for shocks, I initially put KYB Gas-A-Just, but later switched to KYB Excel G, which are less harsh. I also have Addco 7/8" rear anti sway bar with a 1 1/8" front. My rear springs are Eaton Boss 351 @ 153 lbs spring rate, but the 138 lb would have been perfectly fine.
Thanks Stanglover, I remember reading an article before I picked up the 5 leaf HD leafs a couple years ago that talked about stiffening up the back to prevent wheel hop. Since then I have heard several different perspectives on spring rate for leafs and think I may have over-reacted getting the HD's. They are rated at 165 lb. if memory serves. So I am thinking it's going to be a bit of a rough ride but we will see how they react with Bilstein shocks before pitching them and going back to Eaton.
What kind of improvements did you see when you added the 1-1/8" front sway bar and 7/8" rear? Did your car come with factory rear sway bar?
 
Thanks Stanglover, I remember reading an article before I picked up the 5 leaf HD leafs a couple years ago that talked about stiffening up the back to prevent wheel hop. Since then I have heard several different perspectives on spring rate for leafs and think I may have over-reacted getting the HD's. They are rated at 165 lb. if memory serves. So I am thinking it's going to be a bit of a rough ride but we will see how they react with Bilstein shocks before pitching them and going back to Eaton.
What kind of improvements did you see when you added the 1-1/8" front sway bar and 7/8" rear? Did your car come with factory rear sway bar?
Thanks.
I too may have over compensated by going with the Boss springs, but at the time, (I think that was before I upgraded the axle to a Trac-Loc), it was an attempt to help prevent wheel hop. Before that, I had bought the Scott Drake (I think they are) Grab-A-Track 4.5 leaf garbage springs that ended up reverse bending, total garbage! The 138 lbs stock rear spring would have been fine on the back end of a light car.
The car did come with the (whopping!!) 1/2" sway bar, but changing to the 7/8" REVISED Addco bar paired with the 1/18" up front made a marked difference in cornering.
Shocks only damped the bumps. Buy what you feel are best for you and your budget.
My front springs by the way, are the original factory ones. There was no need to change them.
Hope that helps.
 
Thanks.
I too may have over compensated by going with the Boss springs, but at the time, (I think that was before I upgraded the axle to a Trac-Loc), it was an attempt to help prevent wheel hop. Before that, I had bought the Scott Drake (I think they are) Grab-A-Track 4.5 leaf garbage springs that ended up reverse bending, total garbage! The 138 lbs stock rear spring would have been fine on the back end of a light car.
The car did come with the (whopping!!) 1/2" sway bar, but changing to the 7/8" REVISED Addco bar paired with the 1/18" up front made a marked difference in cornering.
Shocks only damped the bumps. Buy what you feel are best for you and your budget.
My front springs by the way, are the original factory ones. There was no need to change them.
Hope that helps.
I thought your car had staggered shocks? I thought the staggered shocks prevented axel wrap.
 
I do have staggered shocks and no they don't prevent wheel hop. They might however, limit the amount.
Thanks for the information, if it's not a cure-all then I will likely nix trying to find the parts to stagger mine. I spoke with an old timer that told me they used to strap down every leaf on the front side of the spring with a leaf lock to get rid of wheel hop and axle wrap. He said it made the car more rigid as well. I will see what mine is like when I get it on the road. If it hops or wraps I will try the leaf locks and see what happens. If it doesn't work I guess it's on to traction bars and maybe even some lighter springs.
 
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