Hello all, I have a problem with a rattle from my engine compartment when my transmission is upshifting during hard acceleration. It has a stock 305 with a performer intake and 600 cfm edelbrock carb and headers added. I talked to the previous owner who added these items and was told that he had bought it that way. The engine runs and idles great with no other problems other than the rattle. It almost sounds like lifter noise but I am no mechanic. I have had several people tell me it may be valve noise or possibly lack of oil pressure. The engine does not run hot (added a 3 core big block radiator) and has a idiot light for oil pressure which I have never seen come on except at start up. Any help would be greatly appreciated.