I just put this 383 motor in my 78' malibu I dont to much about the specs of the motor other then it has a 520 lift cam. Well I got it all bolted up and ready and it ran great. But when I held the throttle in around 2500-3000 rpms it was popping threw the headers. Well the guy told me that he put the cam in himself so I tought maybe he had a lifter too tight. So I went back threw and re-adjusted them NOW the motor sounds like it has zero compression. I have adjusted valves many times and have ever seen anything like this. It really sounds like all the spark plugs are not it. Now my question is what if its a solid lift cam? Im at a total loss, I have read many threads have yet to find anything that could help.