GM Performance Parts: Upgrade and Personalize your Vehicle with performance technology from the legendary GM Performance. GM Performance parts, GM Racing offers an entire line of performance parts and dress-up Accessories for your early or late model GM vehicles. Nothing matches the feeling of opening the throttle of a v-8 Big Block, We have developed an entire line of Big Block V-8 Crate Engines, we will customizer one exactly as you need it at Karl Performance Parts.