C3 conversion for CSX style chassis

[moore_rb]

Originally Posted by joyridin'

Huh? Yes, they were all 10 bolts, which refers to how many bolts are holding the ring gear on the differential. The rear case is being held on by 8 bolts if I recall.

{sigh} so it's going to become an argument.... Ok, fine, but let's argue from facts, please:

Fact #1: A 63-82 corvette ring gear will NOT bolt onto a Corporate 10-Bolt carrier.

Fact #2: A Corporate 10-Bolt ring gear will NOT bolt onto a 63-82 Corvette carrier

Fact #3: A Corporate 10-Bolt Pinion gear will NOT fit in a Corvette carrier (and will not mesh with a Corvette ring gear (nor vice-versa)

Do I need to continue here? The words "GM 10 Bolt differential" mean a lot more than the number of bolts holding anything together, and the number of bolts holding the ring gear to the carrier is totally and completely irrelevant to how strong the assembled unit is.

To put it in "Ford terms": Is a 351 Cleveland and a 351 Windsor the same engine, just they both displace 351 cubic inches?

A 10-bolt is not a 10-Bolt, is not a 10-Bolt...There are at least 3 different GM corporate 10 bolt diff designs... and I repeat again: NONE of them came in Corvettes.

Joyridin- My beef's not with you (none of this is personal). My beef is with misinformation; and your assertion that "all Corvette's used 10-Bolt rears" could be easily misinterpreted by someone (like the 90% of dingaling Corvette owners out there) who don't know all the facts, and the "10 bolt" observation might lead them to think that Corvette differentials suffer from the same stigma as the weaker, 7 inch GM 10 bolts (false) or that the Corvette diff components are interchangeable with trucks or cop cars (also false); and then this falsity gets compounded when you assume that the number of bolts holding the ring gear to the carrier has anything to do with the overall strength of the assembled diff.

Originally Posted by joyridin'

If I were going to invest a fair amount of money in a totally new rear end in my Cobra with my bored and stroked all aluminum S/O, I would go with something a bit better than a Corvette rear end.

So would I; but nowhere in this thread did I (or anyone else for that matter) state that the Corvette diff was the strongest option out there. I did state (and still stand by my statement) that a Corvette diff is going to be MORE than strong enough for the vast majority of Cobra builds (even big blocks), but particularly if one were looking for a strong, capable rear end to put behind a 450-500 HP Windsor. You even stated that your friend's 347 is making L88 caliber power. Well, the Corvette diffs in the late 60's did an ADMIRABLE job of handling the L88's output (unless you can find me a collection of stories out there of L88's blowing their rearends up)... and keep in mind that an L88 Corvette is a larger car, and weighs about 700 pounds more than an average Cobra build.

One reason cast iron Corvette diffs are so easily available today is because they DIDN'T blow up... They outlived the thousands of C2 and C3 cars that rusted away around them over the past 50 years...

If I had the option of spending 1600 on a rebuilt vette center section, versus 2500+ for a beefed-up Jag diff, then I'd be hard pressed to find a legitimate reason to spend the extra $$$ for the Jag piece, ESPECIALLY considering how much easier it is to source a posi carrier for the Corvette diff, versus how much more difficult (and more expensive) it is to find a Jag with Posi.

Originally Posted by my427cobra

A question for Robert (moore_rb):

Isn't the pinion shaft bearing diameter 1.625"?

Cheers
Greg

Yes- You are correct, and I was mistaken. That's what I get for trying to post specs from memory, instead of double-checking my numbers first... Blame my wife- she stopped buying my Ginkgo Biloba supplements a year ago.

Originally Posted by MAStuart

Not a chevy guy so. That did a 65 to 69 Chevelle Camaro Nova ect have for rear ends. I have always been told a 10 or 12 bolt. Does a 10 bolt really have a 7 inch ring gear? How is it measured? Is it the outside Dia ?

late 60's GM musclecars (especially big block cars) came with 12 Bolt diffs (roughly 9 inch ring gear), essentially the same diffs that were used in 1/2 ton trucks of the same vintage)

The first/earliest Corporate 10-bolt diffs (1970-1975-ish) only came in pedestrian passenger cars, and yes: they had a 7 inch ring gears and were not intended for handling large power.

In the later 70's/early 80's. GM began phasing out the 12 Bolt differentials, and began putting a redesigned, beefier, scaled up 10 Bolt diff (first using an 8-1/4 inch ring gear, then later upping it to an even better 8-1/2 inch ring gear) into trucks, and heavier V8 passenger cars (like police cruisers, etc.) some lighter cars and smaller 4cyl trucks still got the smaller 7 inch "early style" 10-bolt, so there are some model years out there where the axles are externally swappable from car to car, but what's inside the case might be strong, or it might be garbage. You gotta pull the cover and see what's inside.

Truck guys are usually the ones who get bit by this the most often, when some guy replaces the 8 inch 10-bolt axle with a 7 inch 10-Bolt from an S10, and figures that because it bolted right in, it must be the right axle.

Then he goes out 4-wheeling and ends up getting towed home with the rear end grinding, clicking, or totally locked up from all the broken pieces inside....


At this point, I've pretty reached my "Peace Out" moment with this conversation...

Tom, I still think your work is a great idea, and is a great alternative to sourcing an expensive, beefed up Jag center section.

Ed Schaider- As always- your contributions to this discussion are thoughtful and well-informed, especially for guys who have to be "Ford guys, using only Ford parts" in their build...

to anyone else, who likes the idea of using Tjd's fancy brackets, and a Corvette diff case in their build, but wants "bigger better stronger" inside that Corvette case, Tom's Differentials (different Tom ) offers a kit for swapping 12-Bolt musclecar internals into a corvette case:

http://tomsdifferentials.com/2011catalog/Pages14-23.pdf