Just based off what I've heard and seen, it seems that a solid axle is going to be better about all around. I don't exactly know what's all done to the engine that's in it, but I'm fairly confident it COULD mess up the rear end and probably would if given time. I've looked at some older threads but about anything kit wise they talk about isn't available anymore. I'd like to keep it chevy, or at least in the chevy family use. Maybe something like a Dana or 12 bolt? I really don't know, it's not exactly new to me, but getting hands on definitely is.

 

So you are not interested in the handling advantage of an independent rear suspension?
Gary Ramadei, a member of this forum, could build you a stock Eaton IRS differential to your requirements.

 

From what I've heard it doesn't make handling too bad, main thing is price and power though. Seems like if you do it yourself you could be all in 4 grand or less on a solid axle that could handle yknow 750+ hp, and you'd get about all of that. An IRS would lose you a bit of power and cost heaps more especially at that power point. I'm 5 grand deep including the car, so it'd be rough dropping more than I spent entirely on an IRS. Again, this is all just from word of mouth, if I'm wrong and drivetrain loss isn't that bad, and prices aren't that crazy call me out.

 

If, IF you're in USA or Canada, you should be able to find a local/regional race car shop that routinely builds from scratch or sets up "stock car" chassis to run a Ford 9" axle on local/regional Asphalt Oval Tracks. When it comes to performance "straight" axles, 'the world is your oyster' when choosing Ford 9-inch. Including hi-grade but Very affordable ex-NASCAR / ex-ARCA, ex-ASA axles, pumpkins, diffs, R&P gear sets, brakes, calipers, rotors, hats, truck arms, shocks, springs, coilovers etc etc. If you're anywhere near North Carolina, there are oodles of auctions of same parts n pieces.
FWIW, until about Five years ago, ALL Cup cars ran axles based on Ford 9-inch (nowadays, ALL Cup cars run IRS in tandem with a trans-diff from the UK).

 

The guys at Horsepower Depot just ran in the 8's with an independent rear set up - you must be pushing some serious power to need a solid axle.

 

You can go 8s with an independent, but you'll pay a fortune for the parts.

I did a DIY solid axle build for my C3 with a 4 link suspension. Came out great, very happy with the result with many years of cruising and low 10s at the track. Used a Ford F150 8.8 rear, cut down to custom size with "Big ford" ends and added 9 inch 31 spline axles. Ford F150 read has 31 splines posi rear.

Basically built is similar to the 4 Link kits on the market, but with beefier parts and better shocks for less money.










Also with the 4 link, I was able to get more tire in there than I could with independent. Here's a link to my build Turbo C3 build

 

Trucks have solid rear axles. You can pick up 70s square bodies all day for less than what you have in your C3.

If you really think you need the solid axle, there are lots of other vehicle choices. Do you already have a 750 hp engine?

 

They ran the 1350's and broke them. Wrong axle, wrong build type for their application. They should have gone to the 1480, 1350 will not last in that application.

 

From my understanding it's a mildly built 454 bored .040 over so technically a bit bigger, that's beside the point. I'm planning on doing a top end kit and turning it to a 489 stroker and later down the line maybe even throwing boost or nos at it. I know I could PROBABLY get away with it right now, especially since it's automatic, but I'd just rather get it done with and not risk destroying a perfectly good rear end someone else could use.

 

Thank you, I'll look into it.

 

Agreed. The only place for 1350 in my book is on the driveshaft. Also I don't know what the weight of that 8 sec car was.

With the straight axle on my 3750 lb C3, the only thing that broke so far 5 Moroso 1/2" studs during the shift from first to second gear on the 4L80E. (probably my fault for not tightening them correctly).



Upgraded to 9/16 diameter studs from a Ford Dually truck. Never had a problem since.


Although, I do spin the tire on the rim during second gear shifts:

 

You sheared all 5 studs at once? Did you check the fit between studs and rotor? Of course, if the 9/16 studs resolved the problem it's moot point, I guess.

 

It seems so far that a solid 4 link would be the way to go, again if anybody has some secret IRS knowledge that I don't feel free to share it. Just remember I'd like to not go broke

 

Read this and contact Gary
https://www.corvetteforum.com/forums...olt-gears.html

 

Yes all 5 at once. They were probably not tightened right, but we'll never know.

 

I agree with Bikespace. There are better platforms out there to work with.

 

I did a Solid Axle swap in my 69. The way I drive, I don't see the handling advantages of the IRS and I will admit that I am Lazy. Most solid axles live their lives from showroom to junkyard with little to no maintenance. I used a Dodge 8.75 because I had some on hand. They are similar to a 9in. Ford in that they use removable center sections so gear changes are pretty quick. I like low gears, so mine has 4.88's. There are many performance parts available, so they are like most things, you can spend as much as you want. They are plentiful and reasonably cheap. I even used the drum brakes. The way I drive, I could not justify the cost to add disc brakes. With this particular rearend, there was no need to modify the battery box or storage boxes. A local Machine Shop narrowed the housing 2 inches on each side for $80. At the time there was no shop locally that re-splined axles, (now there is). Axles were $400. If you go to the junkyard with a tape measure, you may find one that doesn't need narrowed and has disc brakes. The 4 link kit from Auto-Fab Race Cars included everything including QA1 coil-overs was just over $1100. While everyone may not choose this path, It was the right choice for me.

Rick
Big Block 69

 

FYI for the OP, if you go with Big Block 69's 8 3/4 Mopar rear suggestion, School yourself on those rears. Not all 8 3/4's are the same. 489 case center housing is the strong one.

 

That perfectly good rear end in your 79 is probably worth about $200- as a core, so I wouldn't worry about it.

I would worry about adding boost without a computer. Read through @DblTrbl 's thread. If you want to go the route of solid axle C3, you'll be miles ahead starting with a junkyard LS engine.

But I'd consider driving the C3 as is, and saving the drag racing for a different platform. C3s are fun, beautiful cars, even stock-ish.

 

I'm pretty set on the corvette, plus I don't have space even if I wanted to get another car. It's not running or driving right now because I tore loads of stuff out so regardless it'll be a moment before I actually get to anything.