Valve spring pressure and a Stipe cam

[Jim Brierley]

I've also used Isky springs on performance cams. They are very good but shorter so require a spacer of approx. .500", making them more difficult to install.

[hardtimes]

Originally Posted by AL in NY

We may want to ask Don Snyder the source of the springs he sells. The Hardware Products site has another spring that has the same specs as the standard Model A spring. It's PN is 14078. I guess we could put that fatigue question to the Hardware Products people.

Fatigue of a spring is important and hard use will bring out fatigue in sub-standard spring material used.
In a stock A engine, with the light seat pressure originally used there, most any old A spring with correct measurements will run such engine at low rpm, likely forever.
However, we expect more out of model A/B engines these days when they are warmed up / 'improved', so use the best valve spring that can be had, is my view and practice. New old stock LZ springs are excellent , as are Isky valve springs, in my experience. Nos flathead V8 springs have also proved consistent when checked for height/pressure, etc....