Okay I did some searching; this is what I found out. I have an obd0 Ls dizzy on a dohc Zc. When I first got it, it was working fine. It could go as fast as I wanted to. Now I can’t go faster than 3000 rpms or 65 mph. Before this happened my car started to make a little rattling noise now its loud and even does it at idle could this be my distributor bearing.

At first I was thinking it was the tranny making the noise, but after some searching I think it might be the dizzy.
How do I fix this annoying problem without buying a new dizzy?? If in fact that is what’s wrong?

 

try swapping in another distributor and see if it goes away