I had read that '95 and newer s10 4.3 V6 equipped S10's had the stronger 8.5" 10 bolt rear ends. The overall width varied depending on 2 or 4wd. I can't seem to locate the original article with widths. Mounting bracketry would have to be reconfigured of course. This might be a lower cost alternative to an aftermarket narrowed 12 bolt or 9". Anyone here replace a stock rear end with one of these? Thanks.
the largest issue with this, as wil every other rear sway that isnt specifically made for the 3rg/4th gen, is the torque arm mount. Thats the major problem and where the cost will skyrocket if you have to have somebody do the cast iron welding and fab.
I see what you mean about the cast iron bosses to mount the factory torque arm location on the rear end. I dropped the ball on that one.
I still don't know why GM scrimped on the 3rd, and even 4th gen rear end strength.(considering the LT1's & LS's put out even more power) I guess if you want to play you have to pay. Thanks.
If you want to use an 8.5" then a 2ndgen unit is just about perfect as far as width goes. But you still would have to solve the same problem with the brackets and TA mount.
If you want to use an 8.5" then a 2ndgen unit is just about perfect as far as width goes.
A ZR2 has a wider rear than a non-ZR2 4x4 which is wider than a 4x2. So either you're talking 2nd gen F-body or you could specify which 2nd gen S-series you mean.
I don't think any of the S10\S15 trucks came with a 8.5". As far as I know, they always used a 7.5" diff. Either way, it's still not an easy swap because of the third gen's torque arm mount.
If it had an 8.5" and was an easy swap, there would be a thread showing you how to do it already.
I don't think any of the S10\S15 trucks came with a 8.5". As far as I know, they always used a 7.5" diff. Either way, it's still not an easy swap because of the third gen's torque arm mount.
They did.
I don't know what models exactly except for the ZR2 for sure. As for upgrade potential, a 15 year old 30 spline 8.5" with discs beats a 30 year old 28 spline 8.5" with drums.
Probably depends on the exact year and model S10. Not sure on the exact width (try asking on an S10 forum) but you can see how much the axle lengths changed over the years and if it was 2wd or 4wd. While flipping through the catalog, it looks like the KAC10 axles are for what looks like a 8.5". The KAC7 axles are for a 7.5". None of the S10 axles are the same length as a third gen but that doesn't mean the total width isn't close to the same.
This might be a lower cost alternative to an aftermarket narrowed 12 bolt or 9".
I missed that the first time. By the time you're done fabricating bracketry and especially the good, strong torque arm mount, changing the width if required etc, the cost of an aftermarket direct bolt in diff can be very inexpensive. It all depends on how good your fabrication skills are or how inexpensively you can get the work done for.
If it wasn't for the third gen's torque arm suspension, swapping to any better junkyard diff would be easy and cheap. When I put my first 9" under the car, I used ladder bars as an easy way to eliminate the torque arm. It still needed floor modification to make it work but it did work. I now have a narrowed 9" under the car with 4-link suspension and a back half. Not something recommended for the average street car. My narrowed diff is 45" from axle flange to axle flange. I think a factory third gen diff is in the 61-63" range.
A ZR2 has a wider rear than a non-ZR2 4x4 which is wider than a 4x2. So either you're talking 2nd gen F-body or you could specify which 2nd gen S-series you mean.
Hi I was doing a project Buick Skyhawk and started looking into this rearend. Well all the ZR2's do come with the 8.5 but is 63 inches long compared to the stock size. The 94 and up LT35 with a 5 speed manual also had the 8.5 but it was more narrow at 54.5 to 55, this what I seen. I think the ZR2 is great if someone is running wide tires where you can run deep dish rims, use caution because i still believe them axel tubes will need to be shorten. And the last topic its leaf springs not coil, so you'll have to have a Professional weld that in at the right degrees
I may keep my eyes open for a ZR2, 8.5". I did use 2wd, S-10 axles and narrowed my 7.5". Might help figure out width? But nothing is going to beat measuring one in person.
I may keep my eyes open for a ZR2, 8.5". I did use 2wd, S-10 axles and narrowed my 7.5". Might help figure out width? But nothing is going to beat measuring one in person.
you've got that right about one person doing the measurement, some people forget but your right, if it's you, you will remember the numbers. I'm glad you post a picture. Alot of these guys cant measure and just say it's this. I heard it was 54.5 to 55, but your tape measurement shows different lol. For sure I heard but you might have to measure it lol. But the ZR2 was 63. So double check that one. So the 1994 and up had the LT35 and was a Standard was 8.5 for sure. I guess it's the budget you want to spend? I've seen a 1961 Pontiac Catalina with 9.3 it was really heavy duty, but try and looking for parts? Guy was on Ebay selling a 3:73 for $2,500, no housing or axels, for this price I could get a Dana 60 or the 12 Bolt with the torque arm. I was going to use a Chevelle rearend, but you cant find the crossmember that the upper arms bolt to. Had a guy for $800.00 could weld and make up a crossmember in 2 days for me. I seen some ladder bars on Ebay and $100.00 for them, $75.00 for the crossmember for them and call it a day..As long as you have a upper control arm set up your ok. They do have the Triagulated 4 link set up that welds into your frame. So there is ways and placing in certain rearends into these F Body cars. I also seen the 1976 Chrysler New Yorker rearend, 9.25 for $250 on ebay. But once again, alot of these rearends need to be chopped. Have a good day buddy.
