8.8 rear end swap
02-15-2002 | 08:06 AM
#41
Launching!
Joined: Nov 2001
Posts: 271
Likes: 0
From: Wilmington DE
Re: 8.8 rear end swap Not to ruin anything for anybody, but the 8.5 did NOT come in all G-bodies. The only 80's G-bodies it came in was Grand Nationals, Turbo T-Types, and the Olds 442s. The GN/T-types have 3.42 gears, and the 442s have 3.73s. ALL Monte's ended up with the POS 7.5 rear. The 8.5 was in S10 pickups and blazers, but I believe the width is different. As far as the 70s, never really looked into them.
And good luck finding a decent 8.5 out of a T-type for a reasonable price. Unless you are lucky enough to find one in a junkyard and the people don't know what it is....
And good luck finding a decent 8.5 out of a T-type for a reasonable price. Unless you are lucky enough to find one in a junkyard and the people don't know what it is....
02-15-2002 | 10:01 AM
#42
Staging Lane
Joined: Nov 2001
Posts: 56
Likes: 0
From: San Carlos, CA
Re: 8.8 rear end swap [quote]Originally posted by gm_jim:
<strong>The GM 8.5" 10 bolt was in just about every GM full size rear drive car from the mid 70's to when they dropped them in 96. Almost all 2nd Gen f-bodies from about 72 to 81 had them, and high performance G-bodies (Turbo Regal, Monte Carlo SS, Hurst Olds, etc).</strong><hr></blockquote>
See above. There's plenty of basic cores available. Spring perches, torque arm, and axle length would need to be worked out. Many will also have a 2 series carrier which adds expense since it would need to be switched to a 3 or 4 series. Still, I don't see why a fabricator couldn't set these up for $1200 - $1500 with 4.10's. They'd probably sell a ton of them to people on this board and others - I'd be the first customer. One of the major costs in a 12 bolt is that everything is new - it's been 30 years since they were used as original equipment. The 8.5 10 bolt is still in production with plenty of good used cores available.
<strong>The GM 8.5" 10 bolt was in just about every GM full size rear drive car from the mid 70's to when they dropped them in 96. Almost all 2nd Gen f-bodies from about 72 to 81 had them, and high performance G-bodies (Turbo Regal, Monte Carlo SS, Hurst Olds, etc).</strong><hr></blockquote>
See above. There's plenty of basic cores available. Spring perches, torque arm, and axle length would need to be worked out. Many will also have a 2 series carrier which adds expense since it would need to be switched to a 3 or 4 series. Still, I don't see why a fabricator couldn't set these up for $1200 - $1500 with 4.10's. They'd probably sell a ton of them to people on this board and others - I'd be the first customer. One of the major costs in a 12 bolt is that everything is new - it's been 30 years since they were used as original equipment. The 8.5 10 bolt is still in production with plenty of good used cores available.
02-15-2002 | 10:13 AM
#43
Re: 8.8 rear end swap Let's actually throw some prices on this stuff.
Summit prices:
4.10 gear (8.5), $160
Locker/Posi: $425 (avg price)
----------------------------
$685
+Used housing: $100-150???
----------------------------
$835
+posi parts ($75?)
---------------------------
$910
Now you are ready to do the rest of the stuff.
I have personally bought some used 12 bolts over the years, and used posi's. I have ended up rebuilding all of them.
Most of the donor 8.5's will not have posi's and will probably have 3.08 gears IMO.
A used GN rearend is expensive, and rare.
Another cheap solution:
Moser 9" and axles: $800
Used iron third member: $150
New spool and gear: $400
-------------------------
$1350 <---I think this can hit $1500 easily.
Summit prices:
4.10 gear (8.5), $160
Locker/Posi: $425 (avg price)
----------------------------
$685
+Used housing: $100-150???
----------------------------
$835
+posi parts ($75?)
---------------------------
$910
Now you are ready to do the rest of the stuff.
I have personally bought some used 12 bolts over the years, and used posi's. I have ended up rebuilding all of them.
Most of the donor 8.5's will not have posi's and will probably have 3.08 gears IMO.
A used GN rearend is expensive, and rare.
Another cheap solution:
Moser 9" and axles: $800
Used iron third member: $150
New spool and gear: $400
-------------------------
$1350 <---I think this can hit $1500 easily.
02-15-2002 | 10:28 AM
#44
Launching!
Joined: Nov 2001
Posts: 271
Likes: 0
From: Wilmington DE
Re: 8.8 rear end swap Well, with the supposed variety of readily available cores, the chances of it being the right width are pretty much slim to none. So, you may want to add in the cost to get it widened/narrowed and new axles. May end up being worth it, but all of the hidden costs are gonna start adding up too....
02-15-2002 | 11:03 AM
#45
On The Tree
Joined: Nov 2001
Posts: 122
Likes: 0
From: Detroit, MI
Re: 8.8 rear end swap I honestly don't think there would be enough of a cost savings to support going with either a Ford 8.8 or a GM8.5, over the currently offered 9" and 12-bolt.
There's a lot of fabrication work involved.
It might be cheaper for a do-it-yourselfer with good fabbing skills. But I don't see any companies being able to make a good enough profit on it to mass market them. There's a lot of work involved in something like this.
And you're still talking a lot of new parts that are needed. New axles and axle-tubes, backing-plates, new posi, etc.. And after all of that, you'll still have a rear-end that's weaker than a nice 12-bolt or 9".
There's a lot of fabrication work involved.
It might be cheaper for a do-it-yourselfer with good fabbing skills. But I don't see any companies being able to make a good enough profit on it to mass market them. There's a lot of work involved in something like this.
And you're still talking a lot of new parts that are needed. New axles and axle-tubes, backing-plates, new posi, etc.. And after all of that, you'll still have a rear-end that's weaker than a nice 12-bolt or 9".
