Rear Axles and Horsepower ?

[Idaho Slim]

Looks like I might have sold my LT4 :cry, and already the wheels are turning in my head for a future replacement as a dragstrip/Sunday crusier.

My question is, is there any stock rear axle C3 with an automatic tranny that will handle 4.10 or 4.56 gear swaps with 400-450 HP ??

If not, looks like I might go back to a type of car I raced in my 20's, a 70ish Nova with a BB & 4.56's, but I would rather keep being known as the Corvette guy who drag races and is competitive.

 

[6880 Mike]

Probably all of them.

 

[TimAT]

The C3 rear will hold everything you can throw at it- until the tires stick. They can fail with 200 HP as easy as they can with 1000 HP. Just the 1000HP will be more spectacular.

 

[GTR1999]

The stock vette diffs have weak areas, some years worse then others. With that said, yes they can be built to handle power levels up to 1000 hp(full 1480 12 bolt conversion).

The best years to start with are the 71-79's. There is no difference between a manual or automatic diff other then ratios and "HD" side yokes. I have never seen a std yoke fail so I think the "HD" term for yokes is not always what people think.

A stock type build is not going to last in applications with power, hard use, and traction. At a minimum you need a polished and tuned posi, 10-17 HT spiders, fit caps, steel cap on the LH if you're going to launch the car, solid sleeve, ARP RG bolts and US gear or Richmond( NOS) gears. This should be good in the 450 hp range.

For up to 500-550 I build Super 10 bolts using Tom's 30 spline spider( stock almost gone now) Tom's axles, and my own mods. I have them in vettes through out the states and as far away as Australia.

Over 550 you need the 12 bolt conversion using 1350 or 1480 axles, 3.5 1/2 shafts,and 31 spline outer spindles. I just got in a '70 IRS to build one of these. Again the problem will be getting the 30 spline spiders and of course the cost.

My son was blowing up his 10 bolts with 500 hp and a lot of abuse, then I built him a 12 bolt and now he's blowing apart the weak BW ST-10's.

Good luck, if you have questions you can find all the pictures on digitalcorvettes.