Chevy SBC 350 BBC 454 10" 153T 11" 168T Mini High-Torque 4Hp Starter [Satin] it has a square bore

it has a square bore carb flange instead of a spread bore

Speedmaster underdrive pulley kits are built from aircraft-quality material and computer-machined

a gilmer kit is a must for street or strip engines

They are supplied with rubber shock mounts to help them resist coil vibration

if you want more airflow then you should grab up one of these Speedmaster X-Stream air flow top plates

Chevy SBC 350 BBC 454 10" 153T 11" 168T Mini High-Torque 4Hp Starter [Satin] it has a square boreYou can get up to 50 percent more starting power when you pick one of these Speedmaster high torque mini starters. They're 40 percent lighter, as well as 1 3 smaller. That latter characteristic translates into increased ground, oil pan, and header clearance, but both factors can be equally important in a race car. So can features such as full ball bearing construction, which allows these starters to work great while lasting a long time.