Our Summit Racing® steel transmission crossmembers allow you to run a true dual-exhaust system with most popular GM transmissions. They have a patented double-hump design, so you don't have to compromise ground clearance by running pipes under the crossmember, and they're a complete bolt-on deal--no custom fabricating or realignment is needed. They're made from 2 in. x 3 in. boxed tubing (1/8 in. thick) to handle the frame-twisting power of big blocks.