Summit has trick flow heads

The solid roller springs are really serious. 240 on the seat and 500 lb/inch rate so 600 lbs over the nose with a .700 lift cam.

The solid roller setup comes out of the box with 2.00 installed height which is great. It takes a bunch of work to get that much installed height on some of the other heads on the market. A 2.00 installed height can handle .850 lift with a Manley 221424 spring. Not sure what the rocker arm geometry looks like at that lift so it might not be practical, but on paper it works.

People need to remember that these TF heads will have a 78cc chamber so the CR will be higher than with the Edelbrock RPM heads.