ok all,ive got a compression problem.i just bought a boat few weeks ago,it ran ok but didnt seem to have what it should,needless to say it had cracked head,both heads,bad valves few on each,spark plugs way off gap,couple were wet with water and the electrode was gone,ate up to nothing.so we did compression test and its what led up to pulling the heads,besides checking oil and it was milky with water.so i go to reputable custom engine builder and he tests them and says cracked and bad valves,he finds some old ones laying around that match my number and exact heads,he acid washes them,re seats the valve seats,tests and changes all valves that are bad,how many im not sure.they looked great.installed heads and got it all together,fired rt up,sounded great.took it to lake to test run and adjust rockers.well it sounded good and seemed to run ok,just didnt have the power i know this bbc 454 should have.so we come home and do compression test with throttle wide open with 2 dif testers,one being opened rt there,they both read about 50-55lbs,thats all cylenders,wow,very low.were totally puzzled how it runs like it does with low compression.so we do a leak test,we take off all rockers so the valves are all closed nice and tight,we hook up air compressor and pump air into the cylender,intake doesnt leak,but the exaust does.thats on all exaust valves too.remember these are newly rebuild heads and valves,no valves touchin piston contact or anything.although they did on other heads,but that shouldnt affect the new ones.anyone with any help i surely would appreciate it.ive posted on pb and most have helped somewhat,most dont beleive its running at all on 50lbs compression.but it definately is.im located in bakersfield if anyone is local and would like to see.im gonna take heads off and back to guy on monday and see if he might have done bad job.i dont know what else could be

john