I agree with Don S. on the head gasket for the 2 cylinders side by each being a hea gasket. but the other 2 have low compression also, thats why is suggested the timing belt/chain too.
You're right. That particular 305 had passable albeit low compression readings (120 PSI or so on 3,5 and 4,6) when cold but once warmed up it had low readings (30 PSI or so) on cylinders 3,5 and 4,6. It obviously did not run fine, but you couldn't really hear, see, or smell any problems when it was out of the water strangely enough, but when in the water it overheated, pinged, and bogged like crazy.
OK I did the leak down test and found the #2 was bleeding into #3 (head gasket). I took the head down to a head shop and had then check it over and they said that it was fine and not leaking. They all so said that the intake vavles were SS so it had looked like someone had the head reworked at some point but all shoud be good. I will replace all the gaskets and wive it a try. Thanks again for all the help.
