There is a squeak that sounds like it is at-par with engine speed. It's a 355 (350 bored .030 over), with mild performance additions (I can explain if necessary), and a 2speed powerglide trans, in a 67 Impala 4dr. I was told that it might be the flywheel but I thought I tightened the bolts on damn good. Any ideas? Thanks a million, she's my daily driver and it's driving me crazy!!!!