Chevy GM LS STD Main Bearings [4.8 5.3 5.7 6.0 6.2] Featuring a boltin EFI downdraft

Featuring a boltin EFI downdraft injection system and complete serpentine drive kit

Speedmaster electric fuel pump is compatible with alcohol or methanol fuels

We have developed a superior line of heads for modern performance enthusiasts

Aluminum also promotes faster heat dissipation for further cooling of your transmission

and road conditions

Chevy GM LS STD Main Bearings [4.8 5.3 5.7 6.0 6.2] Featuring a boltin EFI downdraftThese Speedmaster main bearings are just what you need to freshen up your engine. Why? They use silicon aluminum bi metal construction. Silicon aluminum is the choice for many of today's engine manufacturers because of its high fatigue strength and superior temperature threshold. Bearing wear is dramatically reduced and the fatigue strength is greatly improved.