I found an 84 Z28 parts car with a CCC 305 and it has a large cap HEI, while my car has a small cap HEI. Can I swap them out and if so will there be any benefits from the large cap? I also got the manual hatch motor out of it and was wondering if I could mount that in my 87 that has a non working electric hatch pull down?

 

Simplicity.

With the coil mounted in the cap, it simply needs a good voltage supply and an ignition feed.
Larger cap has wider spaces between the posts. Less chance of crossfire and increased timing accuracy.

Although there are millions of them in many vehicles, the coil in cap style isn't that great because of the heat that the coil gets. For everyday driving and street/strip use, it's perfectly fine. For all out performance, an external coil style is better.

You can't however change out your small cap HEI for a large cap HEI without doing a bunch of changes. The small cap HEI is completely controlled by a computer. The large cap HEI still has weights and springs inside and uses a vacuum pot to control part throttle timing advance. Although you could drop in the large cap HEI, it would become a simple mechanical system. I doubt a CC large cap can be controlled by the computer that's designed for a small cap.

If you're wanting to get rid of the computer, an old school large cap HEI is the easiest way to go.

 

What a shame, I want to keep my CCC. I figured that there would be some difference that would keep me from using it but that's fine there isn't anything wrong with my small one so why fix what isn't broken?

Would you happen to know anything about the hatch pull down thing?

 

Both the large & small cap ccc distributors can be swapped, the wiring is the same color. Thay make a conversion harness or you can make one, go to a junkyard & get the est harness from each type, then splice in the middle.

 

Here's a picture of one.