This is one of our 440 engines on the dyno. With a 280 degree hydraulic cam, we ran a Teflon seal on the intake and an umbrella-type on the exhaust. The .030 inch over engine made 485hp on pump gas with ported iron smog heads and this small cam. Changing to a streetable 280/286 Comp Xtreme Energy solid roller meant the springs would have to be swapped from the singles to duals. The spring seats were already machined. There was no more room for the umbrella seal on the exhaust, so these were pulled off. With the solid roller, the engine made 530hp on pump gas with a pair of ported 452 heads.