8.5 in rearend
- Thread starter Billy1979malibu
- Start date
If you're looking for a completely new 8.5 new housing and all you will need to build a time machine and travel back to the 1980's. Cause as far as I'm aware no such thing exists. Which is why those rears bring a minimum of $1,500 dollars these days for a used one.
Supply vs demand has set the price on an 8.5"
You will be in competition with G body owners who are looking for a bolt in solution or someone building a Grand National.
What are you building?
You will be in competition with G body owners who are looking for a bolt in solution or someone building a Grand National.
What are you building?
I want one too. I'll pay more than OP.
Looking forward to learning a few things as I rebuild the abused ragged-out rear.
This is too bad. I've learned it is the position/angle/orientation of the 'ears' on the g-body 8.5" pumpkin/housing that was unique.
I never heard of this, it would be the same as the 7.5" in g-bodies.
It's nice there are more options out there now, people use Ford 8.8"s out of certain Mustangs, aftermarket Ford 9", Explorer 9" rears, etc. That said I'm still a g-body 8.5" guy myself, direct bolt in(ok, grab the driveshaft too), less power loss than a 9" and is enough to handle whatever I'm throwing at it. I put in a junkyard unit with almost 200k on it in 1999 (GN had 191k on the last Carfax before a theft/strip) and ran it with just a fluid change until 2017 before having it rebuilt and the stock posi unit was still in good shape, the builder offered to buy it from me but I still have it. The other 8.5" is from a 442 that I just freshened up, looked just fine inside, no idea the mileage. Many out there aren't ragged.
G-bodies had their own C4L set-up that required GM/G-body spec'd mounting points for the housing 'ears'. The arrangement was the same for any rear GM housing intended for a G-body.
GM A-body & B-body cars used a similar rear suspension layout but the actual housings were different vs a G-body. The mount positions for the upper links on the housing pumpkin were probably the same as GM wouldn't invest all that $$ into one design for one line of vehicles (excluding the vette). Since the housing widths were different (wider), the lower link positions would be different (farther apart).
Swapping to a similar set-up converging 4-link & similar width (like what's under a Fox body Mustang) is where there are differences in the housing mount locations/orientation.
To clarify: the other 8.5" rears out there do not have ears (leaf spring rear) or do not have ears in the right spot (A-Body). There are conversion kits with offset UCA and LCA brackets to correct the issue with the ears on the 8.8 Frod and 12-bolt, etc.
If you have an 8.5 that you want to sell and you are within 800 miles of Philadelphia, I'll drive out to you and take it off your hands for $1500 so long as it can at least be rebuilt. I have absolutely zero interest in putting a ford rear in my Monte Carlo; I'd like to use the original equipment for the platform. Currently I have a 26-spline 7.5 with quick performance clutch posi. If I ever build a 7.5 I will use truetrack and 28 spline with 7.625 ring gear. By all accounts, that should survive 350 WHP.
