The Stovebolt Site Forums The Shop Area The HiPo Shop Rear End Swap

Hi all,

Had a quick question regarding swapping a torque tube on my 47 chev 3100. What rear end fits this truck? I was told a 70-81 Camaro would fit, (shy of changing out the perches, etc). I don't have access to measure a Camaro rear end, and would thought I would just start here to see what people are dropping into their 47-53 trucks and have the same track width (drum to drum)

Thanks

I am currently running a 3.42 drum brake diff from an 88 Camaro..2.8L V6 in my 54. It is 62 " from wheel mounting surface to wheel mounting surface....same as the AD truck. It required cleaning off the Camaro mounting hardware and welding on the perches. The rim choice with this diff and front disc conversion was 5 on 4-3/4 with 4" backspacing. Using the 5 lug on 4-3/4 conversion, eliminates the expensive roller bearing upgrade and uses over-the-counter GM bearings, disc/hub assembles and calipers. However, it makes it tough to find salvage rims that meet the specs. I used aftermarket 15X7's on the front and 15X8's on the rear with 235 and 255/70's respectively. This rim clears the discs, the stock, as well as upgraded tie rod ends on the front, and centers the tire in the wheel well in the rear. Given it to do over, I would go 235/70/15 all the way around with 15X7's so I could rotate the tires.

These diffs are found in 3.08, 3.42 and occasionally a 3.73 and the 89 IROC-z is a posi/disc setup with the 3.08 being the most common. It is an Australian built Borg Warner that is used behind a 305 V8....the replacement brake calipers and seals are expensive, but it is another option. Hope this helps.

Dave

Thanks Dave! You read my mind and answered the rest of my questions regarding wheel size and spacing! I know where there's a Camaro rear end of that vintage with posi, discs, and 3.42 gears sitting right now!

Patrick

One thing I didn't mention (isn't that amazing) is that the axle tubes on the Camaros are 2-5/8 not the usual 3". I got all my perches and U-bolts from Tractor Supply (lots cheaper) I used 1/8" X1" flat stock to make a strap shim that I tack welded to the axle tube under the 3" stock u-bolts. It probably wasn't necessary but I just felt better about the fit.

You'll really be impressed with the 4 wheel disc braking...I used a mid 70's Corvette disc/disc manual master (boosted makes the brake twitchy) with adjustable proportioning valve that I can control from inside the cab.

Dave

Dave, I would have to agree on the 'twitchy' braking. I did a volare clip on my last 51 pickup with a brum rear end and a mustang 2 booster. You could sneeze and lock up all fours. It made it difficult to control braking at times with the high pedal since I modified the stock pedal assembly. How much pressure would you say you have to apply compared to a new vehicle with power brakes?

learn to search cause this has been a big subject

http://www.stovebolt.com/bboard/cgi-bin//ultimatebb.cgi?ubb=get_topic;f=2;t=013386#000002

10-4 carolines truck. I looked through the links you provided. I did do a search earlier, however didn't come up with what you did. I guess searching a little 'deeper' helps.

How much pressure? With a manual master cylinder and front discs, which do the majority of the braking, the pressure you apply is dependent on how quick you want to stop!!! Nailing them hard will stop the beast quickly and you've got time to sense what's going on without locking them up.

The problem I experienced with boosted brakes without ABS in pickups, was the tendency of your body weight shifting forward in the seatbelt and you applying more pressure than you needed even with the pedal ratio adjusted. They were okay during normal driving conditions but you had to watch hard braking situations. Once you lock things up momentarily, you will need to be quick to get things back under control. With the non-boosted brakes and an adjustable proportioning valve you can tune your rear brakes so you aren't fearful of locking everything up and loosing steering control. To me, being able to lock up your power boosted brakes with 10-12 lbs. of pedal pressure is like having a 1 lb. pull on the trigger of your favorite rifle. Not much room for error. On my brakes, I want a little more latitude before things start locking up.

Another thing to consider is the size of the booster and getting it plumbed in...especially if you're running an automatic transmission. Interference with the tranny crossmember can be an issue. Several of the Vendors are offering add-on inline pressure multipliers as well as a Hydraboost system that runs off the power steering pump along with the power steering gear box. CCP is selling their unit for less than a vacuum booster setup. I've not tried it yet but it appears to be a viable option.

Dave

pplummer it's tough being a new guy
so welcome
best to search in driveline but you could in ALL categories. i just typed in rear end. i got dozens of threads but only gave you two. there are links with/IN links/threads. enjoy your reading.
sometimes when you get to specific it gets tougher, so limit your search down to simple words here. we're simple folk.
hope it helps you and any others.

I'm using a 1977 1/2 ton suburban 6 lug, 4x4 drum brake rear end, i live in the foothills and have a 3.40:1 ratio and a 292 w/ a T5 hybrid tranny. the offset (rear wheel set back to center the wheel in the fender well) i have is 2-1/2'', not the usual 1-1.2'' that the venders sell. brake shoes are 2.75'' wide, have great stopping power. disc up front. w/ disc you can NOT use stock rims.
SO are you sticking w/ 6 lug or 5 ?????
many questions to answer b4 you make decisions

2.xx & 3.08 are (2.xx great for flat kansas land) geared high but >> it all depends on what you use for engine & trans. 4.xx are better for towing.

my .02
3.73:1 are a favorite choice

I am going to change out to 5 lug most likely due to the choices in steel rims available for aftermarket. Thanks again. Also, I did end up going to tractor supply and finding perches and u bolts! Thanks for that great tip Fla54! 4.99 for each perch and 5.99 for U bolts! Awesome! Better than paying 139.99 for a "kit" plus shipping! :-)