For some background, I bought my 77 corvette about 3 and a half years ago and I daily drove it for about a year. I ended up having to park it due to the rear suspension being in pretty bad shape. All of the bushings were falling apart and there was play in basically everything. During the process of rebuilding the whole rear suspension I noticed that there was a lot of rust right in front of the rear left wheel where the trailing arm bolts up to. At that point I welded a couple plates inside of the frame as a temporary fix so I can put it all back together and then make it a future me problem. Well now future me has to deal with it. It is making the left wheel toe out a little bit with the shims pushing the wheel as far in as possible. I know that whole section would need to be cut out and have a new piece welded in. The diff is also going to need to be replaced because the half shaft is rubbing on the right side of the diff case and is now pretty scored from doing so.
I've talked to a couple shops in the area and I'm most likely looking at around 20-25k minimum to have that all taken care of plus anything else they will find. I've started looking into getting a whole rolling chassis instead which I know will be more expensive but I would hate to do this twice. I was looking at something like the SRIII chassis to stiffen up the car and make it a lot lighter since I would like to take it to a track or do some autocross with it. I can do most of the work myself other than swapping the body and the engine. My question is how much should I expect to spend on something like that? How much of my current car will be able to be swapped over to an SRIII chassis?

 

Well, the SRIII chassis doesn’t solve your diff issues, so not sure why you are headed that direction. You didn’t say if your driveline is stock. If so, you aren’t going to have much fun auto crossing with that. I’m no expert, but I think you would be huge dollars ahead to find a clean rust free stock frame (they are out there), brace it up per the Performance Manual, paint and install it with late C3 performance suspension components. I’m sure there’s folks on here that have well set up stock C3 suspension packages that do well auto crossing, especially with modern tires.
The money you save over the SRIII chassis will allow you to get a properly performance built diff, some motor and trans upgrades, and probably even some nice suspension upgrades. Then you can go serious auto crossing.

Edit: I take that back, I see SRIII has rolling chassis packages that include the diff and various choices of suspensions. Still, it’s a lot of money to shell out if you aren’t complimenting it with the remainder of the car being upgraded. Just my opinion, do what you feel like, it’s your $$$!

 

If your frame needs to be replaced, are you sure your birdcage is in good shape? If you have enough garage space, you can swap the body onto a new chassis. It doesn't need to be more expensive, if you DIY a lot of it. Take a look at some of David Howard's builds, @AllC34Me for inspiration:

https://www.corvetteforum.com/forums...ssis-soon.html

The Corvette section of the Chevy Power Book can be found in Duntov's Tech Tips, http://www.duntovmotors.com/

As a potential alternative, there might be better, cheaper C3s out there, if you aren't wedded to this one, or if your 77 needs extensive birdcage fixes, too.

 

If you’re dead set on having this car disregard, but…


Considering you don’t have the capability to swap the drivetrain and chassis, but are still willing to spend 20-25k to get a 77’ to the point where you want it for track driving, you’ll be significantly further ahead selling the car as a project/parts for someone else. Then putting that money combined with your budget for a new chassis into getting as nice of a 77’ as possible. Considering your budget you should be able to get a very good example which might already have the drivetrain/suspension upgrades that you’re looking for. You’ll be much better off money, labor, and time-wise.

 

Call Wally, he's got frames!

 

25 grand can buy a pretty damn nice c3 around here...

 

No doubt, in the States 25K will buy you one really, really nice C3 ready to hit the track.
Me, I am aware every part of a C3 frame can be purchased. It's just a welding project.

 

I thought the sr III chassis came with c4 stuff. Is that not right?

 

C4, C5, C6, or C7. How much do you want to spend?

http://sriiimotorsports.com/196382corvette.html

If you put a value to your time, you might come out way ahead buying an SRIII chassis.

 

This is going to end up being a very long term build, right now I'm just looking at all of my options, I might end up just keeping this one as a parts car and buying one for 15-20k with a clean frame and then modifying that one instead. I just didn't want to end up redoing this whole car and then deciding I wanted to do an aftermarket chassis and have to do it all again. Thanks for your help.

 

@JGillis, any update on your car? Or pictures?