Sorry, I'm only half-a$&ed with wrenches .... worse with computers ... (all this is just a hobby ...)

.....(WITH REGARD TO MORE PHOTO'S) ..... I'll hopefully get one of my kids to look into it .....

Seriously speaking, the Big Block just puts the C-4 into a whole different league .....

I believe it is the most sophisticated chassis that a Big Block can be "dropped" into.

Will try to answer any Q's I can and I can e-mail you pic's if needed, as time and skills permit.

This conversion was done years ago, and not by me, so to a degree, figuring out what was done is like forensic analysis .....but it runs and drives very well, so it serves as an excellent template for those that might consider the ZR-2 (there's one in the museum) retro-fit.


1) ..... Installed a 468 C.I.D 1970 LS-6 BB that makes 92% of it's peak torque (560 ft.lbs.) between 2500 and 5500 R.P.M.

2) ...... remove A/C etc., etc., ...... Total weight 3270 lbs. 52/48 frt/rr split.

3) ......Installed ZF6, from ZR1.

4) ....... Installed B&M short throw with grafted on custom ebony Pistol grip assembly from Hemi-Cuda ... (it's nice to have something you can really get a grip on)

5) ..... Hoosier R-6

6) ..... slammed with full Corvette Challenge susp.

very simple to work on.

...should pull over 1.3 lat G's ... drives around Ferrari's ....


HERE IS AN EXAMPLE OF A TECHNICAL ISSUE WE WORKED OUT:



Did you do anything with the Clutch Master or slave Cyl. in your swap?

In my case, the combination of parts from the '85 and the '93 seems incompatible and we think that the slave was used from the ZF6, and now in a pusher configuration, but the master was the orig. from the 4+3 which has a spacer block between it and the firewall.

This block was preventing the Master cyl from 27.5 % of it's potential displacement (that's all GM needed from it to work the 4+3), however , that was insufficient for the stroke required by the ZF6 slave cyl., so the clutch was never right and no one was able to fix it until we figured out this basic flaw.

This was possibly responsible for clutch failures that all look like you describe yours.

We milled the block down to get the full displacement and no problem now.

Also check your clutch pedal pivot point rod. They are a very soft steel that typically will be found with up to 1/2 of it's diameter worn away ( because of the hardness of the Master Cyl. piston rod end) which is magnified at the far end in reduced slave cyl. stroke.

Getting the pedal assembly out is one of the worst jobs on a C-4 but it is absolutely necessary.

Drill out the old rod and reinstall a shoulder bolt in its place.

I can now change and/or inspect my clutch pivot in less than 5 minutes.