Designed to fill the void created when milling your cylinder heads and/or engine block. Includes a bushing which raises the distributor .125" and nylon shims that are .030", .060", and .090". The bushing also features a longer and larger diameter pilot to work with the oversize distributor bores found in most aftermarket intake manifolds. Includes 2 distributor gaskets. Fits GM V8 & 90° V6 engines. Made in USA.