Can a computer controlled large cap HEI with the old style L-clamps be used on a TPI with the plenum extension in place be used together. Or is it best to get a screw down cap HEI distributor that came on the 85 and 86 cars?

Sup Foo. you know, for about 1 month Ive searched for the very same answer that you've got. Ive hit IROC-Z.com and nobody could help me out. I asked other 86 IROC-Z members but to come to no answer. Today is your lucky day. Ive got the answer. First of all our 86 IROC Z TPI's had the large cap with the coil mounted on top. this gave very little clearence for the plenum distributer cover. So yes it does fit. You can screw down the dizzy cover in its place. Keep in mind that our Camaro's (some) came with the plastic dizzy covers. When our aluminum plenums get dirty, you'll see the big difference in the colors of the plastic dizzy cover, and the plenum. It also has large 3 large screw holes (plastic cover) but the size of the screws are the same. The size of the screws are the exact same size as the screws that are in the top of the throttle body plate (the little plate that says "TUNED PORT INJECTION." Youll just have to buy some washers to compensate for the large holes. Now you can also look for the Corvette dizzy cover. This one is aluminum and the 3 mounting holes are smaller. Bottom line is that if you have a large cap with the coil mounted on top, it will fit. The "L" shape or the "screw down" distributer cap fasteners have nothing to do with anything, they are just 2 different methods of holding down the cap to the dizzy base. Heres something crazy for you, the dizzy in my 1986 IROC-Z, It belongs to a 1986 Chevy Caprice!!!!! The only mod that I had to do was cut a groove in the ECM connection on the harness to the dizzy to allow for the connector to connect properly into the Camaro's wiring harness. Did I answer your question?