The Goerend Bellville spring is .020” thicker than stock for added strength. The late .780" apply piston is the only style apply piston that should be used with the heavy Bellville spring. Our Laser cut, steel spacer is thinner than the plastic stock spacer to keep the waved snap ring in its proper position. The added spring thickness raises the rear/forward clutch pack slightly, so we include the .060” selective snap ring to maintain proper clutch clearance. We use the Heavy Duty Bellville spring in all of our kits to eliminate the failures commonly seen with OE springs. this kit is a must for high performance applications with forward pressures exceeding 200 PSI.