Ford 331 5.0L Probe Pistons 4.000 X 3.250 X 5.400 X -4.0 CC Flat Top. These probe industries forged pistons will give you 10.05:1 CR with 58cc heads. Compression will be 8.96:1 with 64cc heads. Ring size is 1/16, 1/16, 3mm. These pistons use ring set 315-0049 from Probe (also sold by Stage 3 Motorsports). Call 623-435-0166 with questions on this piston set. Price is for a set of 8 pistons w/o rings. If you need these pistons in .030 or .040 please list this info in the order notes section.
