502 problems.......
 

I have a 1992 502 Mag. w/ about 50 hrs on rebuild (except for pistons and rings). Problem Im having is a misfire when idling, burns a quart of oil in about an hour, one side smokes pretty bad and you can also see oil residue in the water from the exhaust. I have not done a compression check yet, could it be the rings? I hooked up a vacuum gauge and the needle on the gauge is erratic between 17 and 16 when idiling at about 650 RPM. When I bump up the idling to around 1000 RPM the needle is very steady.

Re: 502 problems.......
 

A compressiontest is definitely a good end to start in. Did you rebore the block and change pistons and rings at the rebuild?

Re: 502 problems.......
 

with all due respect, it doesn't matter at this point... whatever is wrong is not going to get fixed staring at it in the engine bay... better to just take it out and strip it and find out for real... from what you describe it is going to be obvious once you look inside.