olds307 and 403
- Oct 14, 2008
The 350 flywheel will work, in fact a 400 and 455 flywheel will also work, same bolt pattern. Just get it balanced to your motor. Remember the 64 to 67 Olds motors with forged cranks have a different crank bolt pattern. The 350 has a lighter piston/rod combo, the later 400 may be lighter, tiny bore but a big rod and the 455 should heavier, same longer/heavier rod but a much big bore than the 400.