16x Intake Guides16x Exhaust Guides

differentials and other related driveline components on cars

which are optimized for limited driving conditions

Safe for E85

tending to become unstable and prone to pivoting under torque

S58 Billet Main Caps by 5150 AutoSport X4 G02 16x Intake Guides16x Exhaust Guides5150 AutoSport S58 Billet Main Caps As power levels climb beyond 1,200+ horsepower, we've seen factory main caps begin to walk. Under extreme cylinder pressure and crankshaft loads, even the slightest cap movement can affect main bearing alignment, oil clearance, and ultimately bearing life. Our CNC machined billet steel main caps are heat treated for maximum strength and feature a dowel pinned design to positively locate each cap and virtually