in the mits of building my drag car keep reading how bad the 7.5 is with any power to it.im putting 500+ down so ive been looking for a 8.5 really dont no what yr, model that will fit i came across this ad let me know what you think thanks for all the help.. http://minneapolis.craigslist.org/pts/1071128902.html
8.5 rear
- Thread starter Lameduk
- Start date
Ok well this is a 1973-1977 A-body car rear diff 10 bolt 8.5. The trouble with these rears is that the lower control arm mounts are all wrong and the uppers are too wide and the whole rear is very wide compared to all GM rears. They were used as FULL size car rears in the 1978-1996. All depends on hpw good the deal is as to the work you want to do.
We do have uppers that will fit that area for you . Lowers wil lneed modifing you might be able to use your 7.5 lower mounts for that. ??? All depends on what you can put up with. Jim
We do have uppers that will fit that area for you . Lowers wil lneed modifing you might be able to use your 7.5 lower mounts for that. ??? All depends on what you can put up with. Jim
The g-body 8.5 10 bolt rears are ONLY for the g-body cars...They do not fit anyother cars. 1984-1987 could be 85-87... Not exact on the beginning of the 8.5 in the g-body...BUT the 8.5 g-body rear will fit all the way back to 1978 and up to 1983 and thorugh to 1987.
The only mod that will need to be done is the driveshaft shortening (about a 3/4")or to buy the correct length drive shaft.
Good luck on that hunt. Jim
The only mod that will need to be done is the driveshaft shortening (about a 3/4")or to buy the correct length drive shaft.
Good luck on that hunt. Jim
if your willing to buy offset wheels, the A body rears, 73-77 will bolt right in a G body, all you have to do is redrill the upper arms( holes are there already) and get a shorter driveshaft. Any junkyard should have a grand prix, regal , etc you can get a rear for cheap.
That is not all total true... Yes they are CHEAP...
BUT ...You have the shock mounts in the front of the axle tube. they will need to have plates welded on for mounting g-body shocks. Then lower control arm mount are way wider making a binding problem spring mounts are wider putting another geometry on the suspension travel off. The upper control arms need to be about 2" shorter or the pinion angle will be way off and u-joint premature failure and vibration problems will be rampant. The width of the rear can be fixed with at least a 5" backspacing offset. I guess in a MAD MAX world you can get anything to fit, but it does take a bit more fabrication then what your saying to do it correct
PLUS now how much work have we done and time and rims we had to buy. If you have nothing but time you could save a lot of money but still end up with a hokey set-up...??? If your going to keep this car I would really look into spending some time thinking about what you want out of the car and then weigh your options . IF you have a 500+ HP engine I am sure you spent some pretty good money to get it to up there, so money spent on a rear diff should not be an issue.1/3 to 1/4 of the engine money spent should not be out of the question for a rear. Consider how far the car will go with out a good diff. ???
PM if you would like some options we might have and we even sell the upper control arms to install that 73-77 housing at least we can make that part of the rear fit correctly for you. Take care. Jim
BUT ...You have the shock mounts in the front of the axle tube. they will need to have plates welded on for mounting g-body shocks. Then lower control arm mount are way wider making a binding problem spring mounts are wider putting another geometry on the suspension travel off. The upper control arms need to be about 2" shorter or the pinion angle will be way off and u-joint premature failure and vibration problems will be rampant. The width of the rear can be fixed with at least a 5" backspacing offset. I guess in a MAD MAX world you can get anything to fit, but it does take a bit more fabrication then what your saying to do it correctPLUS now how much work have we done and time and rims we had to buy. If you have nothing but time you could save a lot of money but still end up with a hokey set-up...??? If your going to keep this car I would really look into spending some time thinking about what you want out of the car and then weigh your options . IF you have a 500+ HP engine I am sure you spent some pretty good money to get it to up there, so money spent on a rear diff should not be an issue.1/3 to 1/4 of the engine money spent should not be out of the question for a rear. Consider how far the car will go with out a good diff. ???
PM if you would like some options we might have and we even sell the upper control arms to install that 73-77 housing at least we can make that part of the rear fit correctly for you.
Take care. Jim
not sure what rear your thinking of, I have done many and a few friends have also...the shock mounts are on the rear, same as the g body. upper mounts are off thats why you have to redrill the upper control arms , but from the factory the stock upper arms already have the holes, you just have to drill them out.
8.5 from a 77 elcamino bolted dirctly nto my old 83 monte carlo i had to redrill the upper control arms and yes, it went right in.used a pair of 15 by 8 steel wheels with 6 inches of backspce. also the awd mid 80's blazer rims fit too, just ugly.
alowerlevel said:
nope, 73-77. Most of the ones I did came out of a 1977 Grand Prix, and is better then the Gn rear , IMO (larger tubes and floater axles)
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