Grand Rock single stack installation kits use an "S-Pipe" designed with a 5" ID outlet for use with a 7" stack that has a 5" OD Outer Diameter base.

The kit piping transitions from 4” below the bed to 5” above the bed. For exhaust systems less than 4 inch, a heavy duty aluminized exhaust reducer/adapter will be added when you select your exhaust size.

All the piping in the kit is commercial grade aluminized steel. All clamps are heavy duty and Zinc coated for durability.