differential/wheel questions

[traenknerperformance]

hey guys, just picked up a 56 3200 that ive been trying to buy off a guy for 10 years. i finally wore him down and we went and picked it up this week. we have a camaro doner car that im using the ls1/t56 out of. ive problably spent 10 hours reading this week to get a game plan, i have it all figured out except the rear. im going to 4 link it and do a TCI MII set up

i decided on a explorer diff that i found yesterday out of a 99. id like to run a 315 tire in the rear. for rims i want to use 5 lug steel wheels with dogdish center caps. does anyone know if there is a car out there that has a wide enough steel rim/with correct back specing that i can do this in a 15 or 16" rim?

the truck also came with a shortbed so we are working on cutting the frame today to fit the short bed

[traenknerperformance]

so you can see what we are starting with.... it was alot nicer when i first saw it 10 years ago, couple weeks of sheetmetal work and sodablasting and we will be ready to spray it atomic orange

[Sillyoldman]

Nice. I can't wait for updates.

[_Ogre]

82-92 camaro/trans am is the right width

[traenknerperformance]

do you know if its a decent offset though? i know we can measure but i figure if somone else has already done the explorer swap with a wide steel wheel there wont be any trial and error and save me some time and money

[_Ogre]

http://www.chevytrucks.org/tech/ifs&rearend.htm scroll way down
i have an 86 trans am rear in mine. 60'' wide, i believe i have 15x8 rims with a 5'' backspace. 15x7 w/ 4'' backspace up front

[Amorget]

Wow, 315s + LS1 + T-56 + 10 bolt rear end... sounds like a distaster in the making. Coming from the world of Thirdgen F-bodies we know the rear end is the weakest link on our drivetrains. I'm a little suprised to see people suggesting them here.

[traenknerperformance]

I have a grand national with a 10 bolt thats a 10 second car... As long as you get good axles and put a nice posi unit it they can take alot of abuse....
Posted via Mobile Device

[Kabwe]

Originally Posted by traenknerperformance

I have a grand national with a 10 bolt thats a 10 second car... As long as you get good axles and put a nice posi unit it they can take alot of abuse....
Posted via Mobile Device

From my understanding the Grand Nationals used the 8.5 10 bolt which is stronger than the 3rd generation f-body 7.5 10 bolt. Those of us who remember that Grand National and have been smoked by them know those things ran.lol So it will be fine.

[Amorget]

7.5/7.65 vs 8.5 are completely different animals. I was only replying to the comment that Thirdgen rear ends are the correct width.

[jackson]

depends on how much motor and how much converter your gonna hit the tires with

[Amorget]

Yes, if you have a 200 HP engine in front of a automatic transmission with no stall, your 7.5" 10 bolt will be ok. He however is using a LS1/T-56 combo, which is a manual transmission and the engine dynos at the rear wheels ~300 HP and 300 ft/lbs bone stock (mine did 294/306).

[OKGMC4]

But the 7.625 in the later third gens are the same 30 spline pumpkin as the fourth gen. Only difference is the 4th gen is 4 inches wider. And those cars came with the ls1 so it can take it. They don't really give until you start modding them out. The trick is to make sure you don't get swindled into a 28 spline 7.5 rear. I also came from third gens (an 82 bird, and a 92 5 speed bird I still have) and have seen some stupid fast cars with the stock rears. Not sure I'd swap one of those into a old rod, especially when the Mustang II and explorer rear are both ford bolt pattern.

[Amorget]

My nearly stock 00 Trans Am nearly ruined the stock 10 bolt. With the AT they survive much better, but with the MT and a set of drag radials, bye bye 10 bolt. I specifically chose the Nitto's over the BFGs because they were less sticky, but one dead hook off the line and the rear end was never the same, I thought I had broken it but luckily it just makes a whining noise. Car has less then 40k on it.

Most of the stupid fast with stock rear ends have the 9 bolt that they installed from ~85 until 89, including the 89 Turbo Trans Am. The Firehawks got Dana 44s from the factory. Even GM knew that the 10 bolt was weak, it was used for fuel efficiency.

[OKGMC4]

Yeah, drag radials are bad news for any stock parts. With regular street tires in 20 years of driving this car I've had to replace 6 clutches and rebuild the "world class" T5 twice. The torque never got all the way to the rear and it's still fine. : )

[_Ogre]

a 3rd gen probably weighed 1000lbs more than these truck too
i run a ramjet 350 that is conservatively rated at 350 hp and a 700r4 that was built to match the motor
there is no way to get this truck to hook-up on street tires, it just becomes a tire smoking monster

[OKGMC4]

I've been thinking...were you planning on any kind of tub? A 315 will never fit a stock wheelwell. I have 275's and a rolled fender lip and there was only about 1/8" clearance on either side until I added a 2" tub and pulled them in a bit. With a 315 I don't think there is a stock steelie wide enough, you may have to go the Wheel Vintiques route or consider mustang wheels to get the bolt pattern right. Some Cobra R wheels would look nice.

[Amorget]

Originally Posted by _Ogre

a 3rd gen probably weighed 1000lbs more than these truck too
i run a ramjet 350 that is conservatively rated at 350 hp and a 700r4 that was built to match the motor
there is no way to get this truck to hook-up on street tires, it just becomes a tire smoking monster

What do these trucks generally weigh in at?

Yeah, no traction makes it hard to break the rear end