GM Turbo 400 TH400 Aluminum Tailhousing with Bushing The Speedmaster block is ready

The Speedmaster block is ready for the street racer or all-out racer with added strength and cubic inches

Keep the air entering your engine clean with our Speedmaster air cleaners

They're 40 percent lighter

Switch out your weak and thin factory retainer plates with Speedmaster heavy-duty bearing retainer plates and make your ride a lot safer

This feature is sometimes called an air gap design

GM Turbo 400 TH400 Aluminum Tailhousing with Bushing The Speedmaster block is readyThese Speedmaster tailshaft housings are designed to fit the stock Turbo 400 transmissions. They are five times stronger and more ridged than stock because they are made from aircraft grade aluminum alloy. Featuring thicker walls and more gusseting than any other manufacturer.