I was in a very similar situation to you a few years ago. Except I caught mine before it exploded. I knew about Mike and Gary's work but didn't have the extra cash to shell out and really pride myself on doing all my own work. I also knew I couldn't ever really let my 600hp BBC out of its cage w/out beefing up the rear-end. After about a year of research and saving up cash I had Mike do one of the first 'Super 10's'. In fact, the name Super 10 came about because we didn't really know what to call it. I couldn't afford the full 12-bolt treatment but Mike knows these diffs really well, what's weak, what's strong, and he put together a package that'd greatly outlive a stock 10-bolt but didn't go overboard since I knew I'd not be seeing more than 600/650hp. It still uses the 10-bolt ring but the pinion, axle stubs, and a few other parts are from the 12-bolt build so we came up with 'Super-10'.....until somebody thinks of a better name. LOL
Back to my point, I talked with Mike and Gary a lot and after I realized all the machining that'd have to be done (I don't own a lathe) and the experience to set everything up just right I realized this was way over my head. Here are some pics of the end result:

 

Wow that looks really good. It sounds like its living under those strenuous circumstances you have put it under. Do you run slicks at all with it?

Heres another thought I had today. These new zr1 corvettes seem to live. I wonder if that is just a beefed up differential out of the C6. Maybe an adapter cross member could be made and bolt it into a C3??? I haven't looked at any pictures yet....

 

A properly built 12-bolt IRS diff conversion would most likely solve your problem. Have long had a 3.55:1 one in my shark.

FWIW, C6 have transaxles...

 

The decision has been made. I have ordered the Autofab 4 link kit and a Fab 9 chromoly housing! I will post pics when it arrives! I even got the Wifes approval this time! Thanks for all of your pictures and suggestions I do appreciate it. It sounds just as costly to do the 12 bolt as it does to just have a solid rear put in. I also have more confidence in a fab 9 housing than a stock housing and this was one of my deciding factors.

 

Yeah...and if they did work there, the Big Mac's would look like the ones on the menu!!!

 

The wife doesn't know yet but the 20x10 inch Boyd's wheels are on the way! Pics to come when they arrive. They have a 6 week build time. June 6th is my date for the welding to begin! The Fab 9 will be modified for the deep lip wheel.... Stay tuned!

 

the autofab kit is very nice and easy to do... we got a few guys on here running em without breaking and putting down some good times..

 

I was speaking with Autofab the other day and I asked them why they say their kit is only rated to 800 hp and they told me because that is all that has been confirmed to run on it so far. They did see they have people running deep into the 8's with it already but the customers have not confirmed the power. That was good enough for me to know.

 

Quick update: Autofab 4 link with fab 9 Chromoly housing has been installed. I also got the strange pro iron case with 3.89's, Detroit locker, and moser 35 spline axles. The rear housing was narrowed to fit genuine Boyds pt-22 wheels in the back(315 35r-20) with 18's up front. Running nitto nto5r's drag radials in the back with the nto5's up front. Nwilwood drag brakes installed in the rear and matching black powdercoated super lights in the front. I also have the gorilla performance master cylinders coming with a bal bar adjuster to get rid of the booster. I have to reinstall my Borla xr1 mufflers.
My car is almost ready to run, I have had super duper long ever extending lead times with my wheels. It has been frustrating to say the least but genuine Boyds have been trying to make it right. Once I receive the wheels which should be in a week I will post all pics. It will be interesting to see how it hooks as well as this new braking system. I can't wait to share my pics.

 

I also have parts for sale that I will not use anymore

Vbp fiberglass spring 360 lb
Diff support kit
Half shaft loops
3 inch half shafts
Rear diff housing with hd cover
Vbp camber kit
Drive shaft
Pm me if anyone is interested

 

Mike you need to post some pictures!

The work on this car is amazing and I've seen it myself. His interior is almost finished too. I'd give it two weeks and it should be nearly complete and ready or CarCraft.

Now, you need to figure out what you are doing with your 4-speed... because that is going to blow up this summer. LOL

 

Thanks for the cred Small Block. You've seen this is the making for quite some time. You are right the 4 speed is holding me back. It needs a Jerico or a liberty tranny, or maybe a paddle shifted tci tranny 6 speed automatic???? I'm not sure what route I will take but it will need to be done soon. Any sponsors out there wanting to give away a race transmission? LOL Well have to talk about where we should take pics at later. The car is amazing and I'm grateful for TNT specialties . TJ and company did a great job on the solid rear axle conversion. Best chassis fabrication shop I know of. what do you guys think about the transmission?

 

Here is a picture of the rear Fab 9 installed:

 

His car is sitting on my stock 87 Monte SS wheels. I can't wait for the PT-22 wheels to arrive. Boyd service is terrible. I would have pulled the plug long ago.

 

sent pm.

 

Everything has sold but the diff. Preferably Id like to get ride of this locally in the MN area.