Mahle Forged Powerpak Pistons, Pins, Locks and Rings. SBC 400 stroker Make: Chevy Engine: 420 SBC/Bore 4.155″ Stroke 3.875″/ Rod Length 6.000″/Crown Volume -22.0cc Dish (2V)/Compression Height: 1.062″/ Weight 452g/ Compression Ratio 10.1:1w64cc/ Pin Diameter.927″Pin/Piston Material Forged 4032 Alloy/Ring Lands 1.0, 1.0, 2.0mm file fit rings/Skirt Type Grafal/Phosphate-Coated Skirt Quantity/ Sold As Kit (for 8 Cylinder). Applications 600hp street, strip, mild nitrous and forced induction. These are a special order item. Please e-mail with questions and availability.