Discussion in 'The Garage' started by 84CUCV, Dec 29, 2006.
heres a pic thanks
Corporate 12 bolt, found in GM trucks up to '82 in which they switched to 10 bolts in '83.
Dont know much about the 12b any better then a 10b?
They're better, by far. Currie builds them. Yep, Currie doesn't do just 9" Ford rears but also 12B rears.
OK what makes them better? Bigger ring gear or???
Same size and spline shafts as a Dana 60 only they are C clip semi floaters instead of Danas full float. Ring gear is also larger than the 10 bolt.
Not much bigger in diameter . 10 bolt =8.5" 12 bolt = 8.875" .
Old school 10 bolts had 27/28 splines side gears while 12 bolts had 30 spline. Basically the 8.5" 10 bolts are a slimmed down version of the 12 Bolt and most folks agree that GM went too far. 10 bolts are not known for strength and 12 bolts are usually considered the basic minimum as a starting point with small tires.
Guess i was wrong
Not really , ha,ha...
It appears that GM wanted to offer the bare minimum that would get the job done and it seems like they found it in the 10 bolt 8.5".
cool thx guys good to know.
12 bolts aren't any stronger than a 30sp 10b. In fact, the 10b has a stronger pinion shaft, and the R&P in general are easily as strong as a 12b. Anyone who replaces a 30sp 10b with a 12b as an "upgrade" is doing nothing but wasting their money.
OK i see thanks
hmmph., cost me 150 bucks to trash my 10blt and go to a 12bolt when i broke the carrier and never had a lick of trouble from that 12b, they are, if only nominally, stronger...
Well, the stock carrier is the major weak point in the 10b. Aftermarket carriers generally hold up nicely, though...
Then again, I am one who pulled a perfectly good 10b from my ride and replaced it with a 14bsf, just in case
By looking at the numbers, yeah it's not much bigger but I put one in my 74 stepside 2WD with a 580 HP 468 and 11" slicks. Yes when I pulled it there were obvious signs of wear. However I'll kiss your a$$ on the 50 yard line on super bowl sunday if you can find a stock 10 bolt that will do that for two years.
Separate names with a comma.