Multiple U.S. Warehouse LocationsBroken ApexFree shipping on qualified orders over $100*
The Mahle MS forged piston set for BBC 503ci engines includes eight pistons with a 4.280in bore, 4.375in stroke and a .990in wrist pin. Matched to 6.385in rods and an 18.0cc crown volume, these pistons produce about a 10.4:1 compression ratio. This set is intended for big‑block Chevrolet builds where precise bore, stroke and combustion volume matching is required for predictable compression and fitment.
Mahle MS Piston Set BBC 503ci 4.28in Bore 4.375in Stroke 6.385in Rod .990 Pin 18cc 10.4 CR Set of 8
