8.5 10 Bolt Build
- Thread starter Michael Bennett
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Well, I think I'n going to put it together as is to see if I like the 3:73 or not. I also have a 2.93 gear set that is in better shape. I'm wanting to stick with the TH350 so that may be a good option. Then i'll have all winter to mess with it. A big part of me playing with this rear end is me learning so I'm not concerned about taking it apart a bunch of times as long as I learn along the way.
You can't use 2.93 gears on a 3.73 diff or a 3.73 gear on a 2.93 diff. You need a 2 series diff for 2.93 gears and a 3 series diff for 3.73.
You'll need this https://www.amazon.com/dp/B001G7END6/?tag=gbody-20 to put the 3.73 gears on the 2 series diff.
My86R3gal - what '81 Cutlass described is spot on. Once the gear is broke it is a matter of time until a catastrophic failure occurs. If you need replacement gears, then Motive gear is what I prefer, but others will say Richmond, Strange, etc. I've had excellent service from Motive gears.
You'll need this https://www.amazon.com/dp/B001G7END6/?tag=gbody-20 to put the 3.73 gears on the 2 series diff.
My86R3gal - what '81 Cutlass described is spot on. Once the gear is broke it is a matter of time until a catastrophic failure occurs. If you need replacement gears, then Motive gear is what I prefer, but others will say Richmond, Strange, etc. I've had excellent service from Motive gears.
Everything I can find and even in the motive gear catalog it lists one carrier break for GM 8.5. 2.56 and down/2.73 and up. Going by that, the carrier from the caprice that currently has the 2.93 gear set should work with the 3.73's, right?
Also, i get it about the chipped gear. It's living on borrowed time, but I don't think it's ready to explode tomorrow.
Also, i get it about the chipped gear. It's living on borrowed time, but I don't think it's ready to explode tomorrow.
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Thanks for clearing it up, I thought he was saying the 30 spline moser axels were trash. I may have misread it. But good info on the gear I was looking up the Richmond 373 gear.
Yeah I might have worded it a bit poorly
30 spine axles are good
Already broken gears are trash
quick performance has the cheapest diff parts I know of. I have read there is only like 3 people that cut aftermarket gears, so if you buy a US standard gear, richmond, motive, or any of the other places good chance you are getting 1 gear from about 2 or 3 total suppliers.
If you are on a budget I'd run those gears. I've used worse. You should see the countershaft in the T5 I just cobbled together for my GP. Use a stone, as on a whetstone or machinist stone to knock off any burrs or highs on the chipped edge and go for it. It may be a bit noisy on acceleration. Hum most likely. Maybe at cruise too.
Combo is a 408" small bock. Zero decked, 5.7 rods 10.7:1, Performer RPM 195CC heads, Performer RPM intake, Lunati Voodoo flat tappet cam Duration @ .050 (Int/Exh): 233/24, Lift (Int/Exh): .504/.525. Flowtech 1 5/8" full length headers, 3" pypes exhaust with race pro mufflers, 28" 275/15/60 Cooper Cobras, and a TH350 with stock stall. Surprisingly enough it actually runs very strong with the current 2.41 gears and no posi so I'm pretty excited to get some gears in it. My plan was to try the 3:73's out right now to see if I can live with the gearing.
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