Designed and manufactured for Dodge Viper engines making over 1000HP.  RSI Billet Main Caps are manufactured in the US with US material. These are the same billet main caps we use in our 1500+HP Dodge Viper engines. 
CAD designed and machined on precision CNC equipment ensures these are made to the highest quality. With a Tensile Strenth of 148,000 PSI these billet main caps are manufactured from SAE 4140 Steel.

RSI Billet Main Caps require machined installation and align bore / hone work.

They also require the use of main studs like the RSI Main Stud Kit for the Dodge Viper.