Bought a boat with a 455 olds. Runs, but did a compression test. Heres the results :
cylinder 1 135psi
cylinder 3 90psi
cylinder 5 0psi
cylinder 7 120psi
cylinder 2 0psi
cylinder 4 140psi
cylinder 6 140psi
cylinder 8 0psi
Ultimately there all low, but what would cause no compression...