iron 408, 4" stroke, 4.030 bore, and 71cc chamber was 10.5: 1 roughly
-8cc piston

What would it do with a 64 cc 243 head?

also, if I milled that down to 61cc or lower what would it be?
If it's milled down 0.030 or 0.020, will it have PtoV problems on a TSP giant cam?

thanks again for all your help gusy

 

what gasket thickness?

These are all with .055 gasket thickness

64cc's = 11.8:1
61cc's = 12.2:1

 

Also if you're going with flat pistons I would assume that you will have major PTV clearance issues with that cam but I'm no expert...

 

sorry, forgot to add that, -8cc piston.