I have been having a lot of trouble with my 340. It just simply has no power and has a very inconsistent idle. Ive posted on here a few times about it but I found out some new info on it. It is a 1970 340 that has a stock bottom end. The heads were shaved just to clean them up and were mildly ported just to smooth out the ports. They are J heads with 2.02 valves. Cam is Hughes whiplash. Intake is edelbrock torker II and carb is 600 cfm edelbrock. The engine was recently honed and new rings installed. I was told that during break in, the engine got hot because they didnt put enough water in it and they had to shut it off after about a few minutes. After it cooled they filled the radiator up and fired it back up... then drove it around to break it in. Since the engine overheated is it possible the rings didnt seal good? I have put maybe 2000 miles on this engine since I have had it and it definitely hasnt improved.