[NHRASuperStock455SD]

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Valve bounce is the problem. We first encounted this when we tried to put Stainless Valves in our tunnel port motor. This motor we shifted in the A/MP car at 9000 RPM. It went 9.41 @ 147mph in 1982 and weighed almost 3500lbs.

We put that motor in a SuperComp car 20 years later, and put stainless valves in it. The RPM's dropped to 6300, and the BSFC went off the map just like all of our other Pontiac motors.

The heavy valves cause valve bounce particularly with a 1.8 rocker and the agressive camlobes we are running.

Don Kennedy and I both are the only 455's in Super Stock left. We both go to 7000k. Our peak HP is about 6300-6400. I havent convinced Don to go with the big springs yet, but I think he will pick up if he does.

I know these springs will work with the E-heads. Of course it all depends on what kind of rocker and cam you are running. However, there is a reason Warren Johnson and most ProStockers, and all the SS/AA Hemi guys are running these springs. Not only valve bounce, they limit spring harmonics from waffling the spring so hard.

When they first came out they cost $1000 with all the keeper and titanium retainers. Now other manufacturers have gotten into the deal and the price is down to about $500.

At 2.100 installed height, the are about 430lbs and over 1000lbs open. (.800 lift)

Lynn