What do staggered rear shocks mean?

[secluff]

scgamecock, just as jpaz posted, it came down to the limitations of the AC compressors. At the time Ford was using York and Tecumseh AC compressors which were as good as any in the 70's. In fact the Tecumseh which had a cast iron housing was used in a lot of F600-F800 trucks with factory air.

The problem with the 3.91, 4.11, 4.30 cars was the extreme load imposed on the compressors when the sudden increase of extreme RPM's subjected them to stress they just were not engineered to handle. In fact in the 60's you could not get AC with any solid lifter engine since Ford knew how they were geared and how they would be driven. (High perf 289, 66 Police Interceptor 428, 427's and all Boss engines)

Hmmm this kinda throws a curve ball at my engine and rear end plans.  I was planning on running a solid flat tappet cam and 3:90 gears. :-/ :-/  I don't plan on drag racing the car so routine high rpms wouldn't be an issue.

Don't let this scare you away from what you want to build. You just need to catch your breath and step away and think about how you are going to use your car. Show Queen, weekend cruiser, occasional driver, or a everyday ride makes a lot of difference. My mention about the solid lifter engines from Ford was in reference to a general non availability of AC and automatic trans since it was generally known how these engines would be used. Anyone that was willing to pay almost $500.00 for a 271/289 (High perf 289) over the 2bl 289 ($105) or 4bl 289 ($158) knew that it wasn't going to be used by Grandma to drive to the  ladies weekly sewing and knitting club.

My high school buddy owned a 70 Mercury Cyclone SCJ 429 with the 4.30 gear. A hour ride in it would have your ears ringing for the rest of the day. Was an absolute blast to drive something that felt like it was trying to push your eyeballs through the back of your head. The NO gas mileage aside, it was just a hot noisy ride where any trips were planned on where the gas stations were.

As David posted you can do as I did in my Mach 1 and just cut the AC off if you thought you were going to get involved in some sort of red light "Confrontation". My 85 GT has a micro switch so when you go to WOT it opens the circuit to the field coil. Nice to have but also just as easy to flip the off switch.

Still your car, as we always say, we all just want to help you make an informed decision. A lot of folks here have the "Been There Done That and Have the T-Shirt". 

 

[7173Vert]

Not sure why the arguing going on here... The facts have been presented and are backed up in many car's on this site. For reference purposes, my 429 convertible came with A/C and the maximum and required 3:25 gears (it also has the trac-lok addition which was an option that the original purchaser would have checked off on the sales order). It also has the staggered rear shocks and competition suspension from the factory, everything that all of the legitimate documentation out there (much of which I have reviewed against countless car's over the year's as many other's here have as well...); confirms was available. There were some odd balls come off the assembly line, so some suspension set up's may have been added or missed, doesn't change the facts as stated...

 

[Don C]

All Mach 1s received the competition suspension, look in the 1971 Mustang Facts brochure, page C-8, under Functional, and on page C-11, Standard Equipment.

My sportroof, with a 351C 4V, came with the competition suspension.

 

[midlife]

scgamecock, just as jpaz posted, it came down to the limitations of the AC compressors. At the time Ford was using York and Tecumseh AC compressors which were as good as any in the 70's. In fact the Tecumseh which had a cast iron housing was used in a lot of F600-F800 trucks with factory air.

The problem with the 3.91, 4.11, 4.30 cars was the extreme load imposed on the compressors when the sudden increase of extreme RPM's subjected them to stress they just were not engineered to handle. In fact in the 60's you could not get AC with any solid lifter engine since Ford knew how they were geared and how they would be driven. (High perf 289, 66 Police Interceptor 428, 427's and all Boss engines)

Hmmm this kinda throws a curve ball at my engine and rear end plans.  I was planning on running a solid flat tappet cam and 3:90 gears. :-/ :-/  I don't plan on drag racing the car so routine high rpms wouldn't be an issue.

Don't let this scare you away from what you want to build. You just need to catch your breath and step away and think about how you are going to use your car. Show Queen, weekend cruiser, occasional driver, or a everyday ride makes a lot of difference. My mention about the solid lifter engines from Ford was in reference to a general non availability of AC and automatic trans since it was generally known how these engines would be used. Anyone that was willing to pay almost $500.00 for a 271/289 (High perf 289) over the 2bl 289 ($105) or 4bl 289 ($158) knew that it wasn't going to be used by Grandma to drive to the  ladies weekly sewing and knitting club.

My high school buddy owned a 70 Mercury Cyclone SCJ 429 with the 4.30 gear. A hour ride in it would have your ears ringing for the rest of the day. Was an absolute blast to drive something that felt like it was trying to push your eyeballs through the back of your head. The NO gas mileage aside, it was just a hot noisy ride where any trips were planned on where the gas stations were.

As David posted you can do as I did in my Mach 1 and just cut the AC off if you thought you were going to get  involved in some sort of red light "Confrontation". My 85 GT has a micro switch so when you go to WOT it opens the circuit to the field coil. Nice to have but also just as easy to flip the off switch.

Still your car, as we always say, we all just want to help you make an informed decision. A lot of folks here have the "Been There Done That and Have the T-Shirt". 

You forgot to mention that the T-shirt no longer fits... :whistling:

 

[secluff]

midlife, ahhhh... all I can say is your right! But that is also why I am glad the VIP lounge has an excellent gift shop with A LOT of plus size Shirts!  

 

[Hemikiller]

All Mach 1s received the competition suspension, look in the 1971 Mustang Facts brochure, page C-8, under Functional, and on page C-11, Standard Equipment.

My sportroof, with a 351C 4V, came with the competition suspension.

Yeah, but it's like talking to a brick wall. 

Here's the 72 and 73 Mach 1 facts book page excerpts - Comp Suspension - STANDARD

73 front coil spring - no "63R" is the standard spring chart, only the HD - Compeition Suspension chart. 73 rear leaf listing from the MPC - notice there are only 2 "63R" listings - Mach 1's body code - both are "W/competition suspension". CS was optional on everything else except with the 250-6cyl.

 

[red351]

Some of you guys need to fully understand what your reading. Where is it said that ALL mach's is entitled Comp Suspension. This sound like the lady selling her mustang... Saying, this is a 429 car , because my boyfriend told me so....Well I'm still only going to give you what this 73 H code title parts car is worth... Which reminds me tomorrow, I need too get more popcorn...

 

[Don C]

Please post your Marti report in the Marti Reports section under the Forum tab.

 

[red351]

I'm looking for the forum tab, just like the entitlement. Explain in detail step by step. This old man has a scanner, Just never needed it.

 

[red351]

Time wasted, but here we go

Carefully read pg. 8 under( functional) not just the underline

The complete paragraph and note (351 4V and 429)

Still on pg. 8 under (Variable Ratio)

Vehicles equip with Comp. Suspension

Now pg. 11 under (Comp Suspension)

Again carefully read

Standard on (351 4V and up) Mach 1 Boss351 429 CJ or CJ-R

I standby my statement, the Mach 1 option was only eye candy

Mach 2V engines got standard suspensions, the same as 2V Sportsroof

The Comp Suspension option could be ordered for the 2V engines, but was not standard

The last pg. shone only state for 63R bodystyle

302 351 2b (with/ CS package) option available

351 4b (with/CS package)

It's all clear, and in writing. But then some folks only hear what they want too hear

Just like the lady selling the mustang

It's clear

63R body style 302 351

 

[Don C]

One more try,

Page C-8: The (351 4V and 429) refers to only the preceding "extra heavy-duty front stabilizer bar", not the entire sentence.

Page C-11: Nowhere does it say "Standard on (351 4V and up) Mach 1 Boss351 429 CJ or CJ-R"



Finally, go to page 15 of the 1971 Mustang Brochure and read under Standard Features - Mach 1, no confusing parentheses

https://www.7173mustangs.com/thread-1971-brochures?pid=236176#pid236176

 

[red351]

Your right Don, its pg. 12. I wish I had computer knowledge to make it easier.

It starts under heading REAR SUSPENSION

Paragraph starting optional CS

to Line 5

351 4V and up.

The next sentence goes as

The CS is standard the mach 1 Boss 351 429 CJ CJ-J engines

It's confusing the facts but, as stated (351 4V & up)

cancels that all Mach's get standard CS.

It's Marketing BS

I'm glad hemi posted the 71 illustrated facts. Its much more detailed

than my 72 version.

No Marty report for my 72, because Marty can't tell me anything that I already don't know

I do have reports on Mach's that I sent to junk heaven years ago.

 

[Hemikiller]

Your right Don, its pg. 12.   I wish I had computer knowledge to make it easier.

It starts under heading  REAR SUSPENSION

Paragraph starting optional CS

to Line 5

351 4V and up.

The next sentence goes as

The CS is standard the mach 1 Boss 351 429 CJ CJ-J engines

It's confusing the facts but, as stated (351 4V & up)

cancels that all Mach's get standard CS.

It's Marketing BS

I'm glad hemi posted the 71 illustrated facts. Its much more detailed

than my 72 version.

No Marty report for my 72, because  Marty can't tell me anything that I already don't know

I do have reports on Mach's that I sent to junk heaven years ago.

I'll admit that the 71 entry is written poorly, and can be confusing. They finally cleared it up in '73 - seems pretty straightforward to me. Notice the use of "again" in regards to the 351-4V engines, which implies it is the same stuff as last year, '72 - which was the same as '71. They reworded it because the 71 & 72 books were written clumsily and you weren't quite sure what you were getting. 



I've posted extensively trying to clear this up for you - MPC spring charts, fact book entries etc. All you've posted is your insistence that you're right and everyone else is wrong. You can say it's "marketing BS", but it's not. The spring and shock charts don't lie. There's not a listing in any of the MPC for a "63R" under "standard springs", only Heavy duty (CS) just like the '73 charts I posted. It's the same for 71 & 72. If you look through the Marti reports section, you will not find a report on a Mach that lists "Competition Suspension" as an option regardless of engine option- because it was part of the package. You will find coupes, convertibles and sportsroofs with CS listed as an option, but not a Mach.

 

[secluff]

red351, have watched this discussion about your misunderstanding concerning  the proper applications of the Competition Suspension for the past couple of days. You can rest assured that the info Hemikiller and Don C have given you is as good as it gets. That's why so many people come here from other sites because of the correct info, knowledge and experience here.

I grew up in a Ford family and have been around these type vehicles my entire life. We've had just about every year mustang built from 1966 through a 2019 my brother has on order. I've dealt with Ford Motor Company both directly and at the dealer level for almost 40 years. So I have a pretty good handle on what is and is not on these cars. But....if there was something I did not know or understand or needed further info or clarification on, Hemikiller and Don C would be my first stop. There is a reason Hemikiller is a Tech Advisor (and Don C should be). They have extensive knowledge and experience and would never steer you wrong. And that....you can take to the bank!!  

 

[red351]

Are we all clamed down now

 

[midlife]

Here's an example of shocking staggered rear....

 

[secluff]

midlife, now that.....is a big block staggered rear end!

 

[MaddMike]

scgamecock, staggered rear shocks were not a stand alone option. The competition suspension was standard on the Mach1 (regardless of engine size) and the staggered rear shocks were included with the 4bl 351 and 429 engines. The competition suspension was an option on all other Mustangs except the 250 6 cyl and was a mandatory option on any F60x15" equipped vehicle.

The staggered rear shocks were Ford engineers attempt to control rear axle wind up. With the sudden application of large amounts of torque (such as on 4sp cars) the differential was twisting and causing the leaf springs to twist and the rear wheels to bounce up and down. From 68-70 Ford used staggered rear shocks on 4sp cars. From 71-73 Ford also included the staggered shocks on A/T equipped cars with 4bl engines.

The Drag Pack option was only available on the 429 cars and included many engine enhancements and a choice of 3.91 or 4.11 differential gears (3.91 or 4.30 on Torinos). AC was not available on Drag Pack cars.

My '71 originally came with a 302 2bbl, C-4 and a really weak rear gear. Since restored it has 351c 4bbl, FMX with a shift kit and 9" 3:25 gear. My car came with both rear shocks on the front-side of the rear axle. Should I stagger them? And if so, is there any other pieces beside the lower rear shock plate? Assuming the top end uses the same shock mount hole.

 

[Sheriff41]

I say it's not worth the effort or money. The top mount on the left is different for the staggered setup. Good springs, shocks, and clamping the leafs will take care of the wheel hop issue the staggered shocks were meant to control. Other options are Traction Master bars (some welding required) like Shelby used, or the Calvert traction bars (no welding).

 

[Hemikiller]

The driver's side shock on a staggered shock car is mounted behind the axle. It uses two of the passenger side lower shock plates, and a special upper mount welded to the trunk floor.

Like Sherriff41 noted, it's really not worth the effort to retrofit this setup. It causes issues with exhaust fitment, and there are much better ways of handling axle hop.

 

[Stanglover]

On my 71 Mach, which came as a one-wheeler-peeler with 3.25:1 open dif, my fix was to convert to a taction lock dif, still 3.25:1. Then at first, I went with 4.5 leaf Grab-A-Track rear springs, which turned out to be total crap (don't get me going!). After ditching them, I installed Eaton's Boss 351 (153lb spring rate) and added an Addco 990 rear anti-sway bar. Now, the motor is not a high hp one, so I don't burn rubber for the fun of it, but the wheel hop is gone.
On your car, you could do much the same, except Addco (and others) make a sway bar that attaches directly to the springs, just in front of the plates. With good shocks, mine are KYB Excel G (switched from KYB Gas-A-Just) I think you can eliminate most if not all the wheel hop.
Personally, I don't like seeing traction bars hanging down under the axle.