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Hi,

Ive got a 55 chevy pickup, 2nd series (shortbed 1/2 ton truck). I am considering a rear end swap. Id like to figure out what car could be a donor car for a rear end. Ive got a 350 (mild) and a turbo 400 (no overdrive). What rear end ratio should i look for (id like it to be quick off the line but able to cruise doing 70 without revving out)? Also, does anyone know what car could be a donor car (same sized rear end)? Thanks

Clark

2nd generation camaro/firebird with a 3.08 or 3.43 ratio would work well.

The 12 bolt truck axles from mid 80's would also work but you might get a numerically higher ratio.

You need to find one about 60 inches wide. Check out http://50chevy.freeservers.com/ for more good info regarding possible donor vehicles.

There is also a question on bolt pattern. If you want to keep the 6 lug pattern, you'll want to consider a 4x4 truck diff.

Id like to swap to the five lug, since ill be doing a 5 lug disc brake conversion up front.

Is the second generation camaro/firebird the 1970 - 1981 years?

rusty55, going to 5 lug, Huston54's advice is right on, that will get a 5x4.75 bolt circle using the Camaro diff. That's a common GM size for the intermediate size cars, wheels will be easy to get. If you go with a truck diff, GM 2wds have a 5x5 bolt pattern, as do some Caprice/Impala models, mainly police cars.
skraps-'67-'69= first gen, '70-'81= second gen, '82-'92=third gen, '93-'02= fourth gen. Supposedly the fifth ge Camaro is due out next summer, but I wouldn't hold my breath on it.

thanks for the advice. i am getting a firebird rear (2nd gen) that'll fit. its got 373's supposidly, but if its too steep ill find something a little milder. any suggestions on how to mock up the position that the saddles (or spring perches) need to be in to set my pinion angle correctly? thanks again.

clark

my rear is a 12 bolt w/ 3.40:1. i'm running a T5 Hybrid also.also available is 3.08 && 3.73
mid 70's 4x4 burb /truck works well

Suspension Measurements

REAR SUSPENSION:
The following is a general list of rear ends and their dimensions to help narrow the search for a possible candidate to replace the torque tube rear end or just get a better set of gears for highway driving.
Advance Design Trucks seem to be using rear ends with widths ranging from 58"- 62". I'm not sure of the Task Force width ranges at this time.
Contributing information were Bob Welch, J Forbes and various locations throughout the Web and Automotive Magazines.
Rear Axle Measurements
MEASURED ACROSS WHEEL MOUNTING SURFACE
56 1/2" 71-77 Ford Maverick 8",
57" 71-74 V-8 Mavericks 8", All '75-77 6's & 8's Maverick 5 Lug 8", 49-51 Ford, 57-59 Ford 9"
57 1/4" 64 1/2 - 65 Mustang
58" 78-88 Mid sized GM Car, Malibu/Monte Carlo (82 up Metric Studs), 80 Granada & Lincoln Versailles,
67-70 Mustang/Cougar/Fairlane, Regal with 10 bolt axle, S-10 P.U., 65-67 Nova
58 1/2 " Ford Grenada
59" 68-83 Corvette
60" 55-64 Chevy Car, 67-69 Camaro, 64-67 Chevelle, 68-74 Nova, 71-73 Mustang/Cougar, 84-95 Corvette
60-61" 64-69 1/2 ton 2wd Chevy/ Some GMC 6 lug rear end 12 bolt Coil spring set up Possible gear ratio's 3.70
62" 64-77 Chevelle, 73-76 Torino, 89 Trans Am,
70 2wd 6 lug rear end 12 bolt Possible gear ratio's 3:08, 3:40, 3:73
70-81 4wd 6 lug reared ...............................................................
71- Newer 2wd trucks use a 5 on 5 lug pattern
71-76 Full Size Cars " "" "" "
60" 60's GMC and some Chevy's Dana 44 or Dana 60 with leaf springs 6 lug, Gear ratio's 3.21 to 3.92. GMC V-6 used a 3.21 Dana 44 used a standard chevy 1310 yoke, Dana 60 used the heavy duty yoke which takes the larger 1350 yoke.


Approximate rear end widths measured from backing plate to backing plate.
Add Width to compensate for drums as follows:
4" - 5" for small cars 5" - 6" for intermediate cars 6" - 8" for large cars
48" - 49" 50" - 51" 52" - 53"
'71 Colt
'72 Cricket
'72-75 Datsun Pickup
'72-73 Mazda '65 Ram American
'74 Valiant '28-40 Ford , '57 - 59 Ford
'62 Buick Skylark, '67 Chevrolet Six
'67 Mustang Six , '68 AMX
'69 Javelin Six , '70 dodge
'70 Duster , '71-77 Maverick
'71 Comet , '71- 72 Pinto
54" -55" 56" -57" 58" - 59"
'39 -48 Chevrolet, '68 GTO
'41 -48 Ford, '68-72 Chevelle
'55 -57 Chevrolet, 68-69 Fair lane 6 or 8
'66 Falcon, '69 Chevrolet
'67 Mustang V-8, '69 Firebird
'69 Cougar, '71 -73 Nova
'73 Ventura, '73 Mustang '36 Plymouth, '54-56 Ford Pickup
'67 Lincoln, '69 Dodge
'69 Dodge Van, '71 Torino
'72 Cougar, '74 Pontiac '49 Plymouth, '61 Chevrolet Impala
'65 Cadillac, '66 Buick Wildcat
'66-67 Chevrolet Big Car, '72 Charger
'69 Oldsmobile 88, '72 Chrysler
'72-73 Torino


STOCK CENTER TO CENTER SPRING PERCH DISTANCE
25" 39" 42" 42 1/2
'68 - 72 Chevelle '71 Colt
'73 Mazda '68 -71 Fairlane/Torino
'49-51 Ford '69 Chevrolet
'69 Nova
'71 - 72 Pinto
'73 Ventura
43" 43 1/2" 44" 46 1/4"
'65 Ram American
'64 1/2-'65 Mustang
'67 Mustang
'70's Ford Grenada
'69 Firebird
'70 Dodge '71-77 Maverick
'70 Duster
'70 Nova
'71 Comet
'72 Dart
'72 Cougar
'74 Valiant '57 Ford
'67 Chevrolet Six
'68 AMX
'69 Javelin Six '69 Dodge
47 1/2" 48" 51" 57 1/2"
'39 -48 Chevrolet
'67 Chevrolet big car
'72 Charger
'72 Chrysler '69 Dodge Van
'69 Ford Van '67 Lincoln

BACK TO TOP OF PAGE


The following list of extensive information was contributed by R. Welch:

Original Vehicles
Rear Suspension Width (Flange to Flange)
Year Classic Vehicles Width
26-39 Plymouth-Dodge car/pick up 56-58"
40-52 Plymouth-Dodge car 60-62"
26-39 Chrysler/DeSoto Car 60"
Most Early Mopar's 56-62"
25-39 Chevy Car 56-58"
26-46 Chevy Truck 56-58"
40-48 Chevy Car 58-60"
49-54 Chevy Car 58-60"
47-54 & 55 1st Series Chevy Truck 60-62"
Most Early Buick,Olds, Pontiac 58-61"
28-31 Ford Car/Pickup 57 1/2"
32 & 33-34 Ford Car/Pickup 56 1/2"
35-48 Ford Car 57-60"
35-41 Ford Pickup 56-60"
49-58 Ford Car 57-58"
49-56 Mercury 57-58"
49-51 Mercury 61"
64 Falcon 58"
67 Cougar 60"
55-59 Chevy Pickup 62"




Donor Vehicles Front and Rear
Suspension Width (Flange to Flange)
Year Classic Vehicles Width Front Width Rear
74-79 Ford Mustang II/Pinto & Mercury Capri/Bobcat 55 ½" 55 ½"
71-77 Ford Maverick with 8" axle 56 ½"
75-80 Ford Granada with 8" axle 57 ½"
64-66 Mustang 57"
67-71 Mustang 59"
72-73 Mustang 60"
67-69 , & 60" Camaro 60"
64-67 Chevelle 60"
55-64 Chevy car 60"
65-67 Nova 58"
68-72 Nova 60" 60"
78 & up Monte Carlo, Regal, etc. with 10 bolt axle 58" 58"
68-72 Chevelle with 10 bolt axle 61 ½"
89 Trans AM (Disc brake) 62"
76-80 Camaro/Firebird 61 ½" 60 ½"
68-83 Corvette 58 ½" 59 ½"
84-95 Corvette 59 ½" 60 ½"
Early 70's "A" body (Dart/Duster) with V8&3/4 axle 58"
"E" Body (Cuda) with V8&3/4 axle 58"
Dodge Dart 59" 55 ½"
Plymouth Volare & Dodge Aspen 61" 60 ½"
71 Blazer (6 lug) 63 ¾"
75-78 Granada 9" (43" perch to perch) 52 ¼"
75-78 Maverick 9" (43" perch to perch) 56 ¼"
81-87 Olds Cutlass 58 ½"





FRONT SUSPENSION INFORMATION

Track Width of Popular Donor Car Clips
Manufacture Model Years Track Front/Rear Curb Weight
Chevrolet Nova 68-74 59.8-59.6 3,770
Buick Apollo 68-74 59.1-58.8 3760
Pontiac GTO 68-74 59.9-59.6 3880
Chevrolet Corvette 68-83 58.7-59.5 3655
84-95 59.6-60.4 3890
Chevrolet Camaro (Z28) 76-80 61.3-60.5 3820
Pontiac Firebird (TA) 76-80 61.3-60.5 3900
Ford Mustang II 74-79 55.6-55.8 3305
Pinto 74-79 55.6-55.8 3305
Mercury Capri 74-79 55.6-55.8 3305
Bobcat 74-79 55.6-55.8 3305
Chevrolet Monte Carlo 78-86 58.5-58.8 3235
Buick Century 78-86 59.0-58.8 3700
Pontiac Grand Prix 78-86 58.9-59.0 3735
Plymouth Volare 75-79 61.0-60.5 3395
Dodge Aspen 75-79 61.0-60.5 3395
Dodge Dart 76 59.2-55.6 3600

Table taken from "How to Build a Custom Classic Truck" Peterson Publication; June or July 1999
Written by: Don Emmons & Mike Briggs

Want to know about swapping out a rear end.
and what to use Here's food for thought.... on 50’s chevy’s By: Jim Forbes


The 82-newer Camaros are wider than the older ones, so you should stick with the 70-81 models. The 75-79 Nova uses the same rear as these older Camaros, I believe. The 68-74 Nova chassis is the same as a 67-69 Camaro; the 75-79 Nova chassis is the same as the 70-81 Camaro. The 82-newer Camaros used the small 7.5" rearend design that the 78-newer Malibu/Monte Carlo/regal/cutlass etc used, but it's quite a bit wider. Some of the 82-newer Camaros used different rearends, such as the Dana 44, and some wierd Australian rearend. Of course, if you want to make sure, get out your tape measure and check yourself! I may be wrong.
Here's another one from Jim on the subject----

There are lots of rearends available! Some fit better than others. For 6 lug rearends, the 64-69 1/2 ton 2wd Chevy (and some GMC) trucks have a 12 bolt rear, about 60-61" wide (I measure them where the wheels bolt on). The 70 2wd and 70-81 4wd have a 6 lug 12 bolt that is a couple inches wider, but will fit under an AD or Task Force truck as long as you don't get too wild with wheel/tire width. The 12 bolt truck rearends from the 60s usually had 3.70 gears, which is a bit much for extended highway driving at 75 mph. .

You can swap the differential carrier and ring/pinion gears from a later TRUCK or VAN 12 bolt, the 70s trucks usually had 3.08 or 3.40 gears. Of course, you'll need to know how to set up ring/pinion gears, bearing preload, and all that other neat stuff to do this. These 60s truck 12 bolt rearends are from coil spring trucks, so the perches are in the wrong place, and they have some extra stuff on the housing for a panhard bar, which you won't need with leaf springs. Most 60s GMC trucks, and some Chevys, had Dana 44 or Dana 60 rearends, and leaf springs. These rearends are 6 lug, about 60" wide, and will bolt into a Task Force truck (with some fudging, the perches are about 1/2" too far apart). The brakes use different parking brake cables, which is a problem, and the drums have a different offset. Gear ratios range from 3.21 to 3.92 normally, the 3.21 is found behind some GMC V-6 engines, and is a nice ratio for an old truck. The Dana 44 uses a standard Chevy 1310 yoke, but the Dana 60 uses a heavy duty yoke, which takes a larger 1350 series ujoint. A similar Dana 40 rearend was availalbe as an option in 59 Chevy trucks, equipped with positraction...rare, and with a 3.92 ratio. I have one of these rearends, it was in my extended cab truck...I'm saving it for when I build a race truck (one of these years).
The 71 and newer 2wd trucks use a 5 lug 5" bolt pattern, same as the 71-76 full size cars. There is not much available in the way of matching front brake rotors that will fit an old truck, so this rearend is not too popular a swap, unless you get the 70-up 4wd 6 lug axles. Chevy also used 10 bolt rearends in lots of cars, in varying widths. A common one is the 61" wide 70s vintage Camaro/Chevelle/Nova (and clones) 8.5" rearend. In Camaros/Novas it has leaf springs, but the perches won't work with old truck springs. In Chevelles, it has coil springs, with lots of extra brackets to cut off, and the cast in mounting "eyes" on top, where the upper control arm bushings fit. Wheel bolt pattern is 4.75", and there are front disk brake kits available to match, or you can use the 53-54 car front hubs/drums on the original 50s truck brakes, to get the same bolt pattern front/rear. This is a good rearend for using in an old truck, the ratios are commonly 2.73-3.36, with higher gears available. The axle shafts are usually worn out in these things, so check them (pull the cover, lockpin, and C clips out to get them loose) where they ride in the wheel bearings...before buying the rearend! The 55-57 Chevy car rearend is almost a bolt in, the perches need to be relocated to the top of the housing though. It has the 4.75" bolt pattern, and ratios are usually 3.55-3.73, but sometimes you'll find a 3.36. The 78-88 mid size GM cars use a 7.5" 10 bolt, which is about 58/5" wide. This rearend would work well in an early (older than 47) truck, but it is quite light duty. Ratios are usually 2.29-3.23, which means you want some torque in the engine to pull it...but rpm will be low. This is a coil spring rearend, with all the mounting brackets that need to be cut off. The Ford 8" and 9" rearends come in a whole bunch of varieties, and only a few are usefull in oletrucks. The late 50s full size cars have a nice one, but it's not easy to find brake hardware, drum, etc anymore. The mid 60s midsize cars, such as the Fairlane, have a rearend that is about the right width, and would be a good candidate...if you can find one. The Maverick/Granada is very narrow, about 56.5", and would not fit anything but a very early truck, or perhaps a tubbed Pro Street truck. The 60s full size Ford car rearends are usually too wide, but if you find one, measure it and see! Most earlier full size, and all mid size, cars use the 4.5" bolt pattern, while later full size cars use the 5" pattern. The Ford trucks have a big 5 on 5.5" pattern, with a big center that takes some work to redrill to anything Chevy. Ratios range from 2.47 to 4.30, and the axles come in 28 or 31 spline varieties. There is lots of interchange possible with the 9" rearend, which is why it's so popular...I have one in my 55 Belair, and in my 57 Suburban chassis. Unfortunately, they are getting expensive, especially when you have to shop around for just the right one that will fit. So...if you don't know if a rearend will fit, or what it came from, get out your tape measure and see for yourself! The most important things are overall width, and wheel bolt pattern...then concern yourself with ratio. I like a 2.75-3.0 ratio for a V-8 powered truck that will spend lots of time on the highway; about 3.2-3.7 for a 6 cylinder or small V-8 for in town and limited highway use, and the stock 3.9-4.56 ratio is great if you have to use your truck to haul lotsa weight, and you don't have much engine...just don't plan on going much faster than 55!