mikem350

I just pulled the engine in my '66, which is a '73 model year 454 with flat top pistons. Bore is stock and cyl walls look perfect. Ran perfect also.

Question is, what is the correct dot orientation on the pistons. All 8 face the same direction, to the Pass side

What would approx compression be with my 391 heads (106.9cc). I figured 9:1, and is there enough clearance for a .540 lift cam?

TIA Mike

knight37128

The heads on big blocks have the intake valves on the same side.

9:1 is close if you use a small head gasket. 8.5:1 is closer. Might even be 8:1 if the block has not been decked.

Most (big block pistons) will take a .600 lift cam with no modifacation.

mikem350

Thanks, makes sense now! This LS-4 motor was 8.5 with open chamber heads (assuming 113 cc). So, I calculated about 9:1 with the smaller chambers.

Now to find a good gasket set