Fortunately, there's a pretty wide span of "acceptable" valve spring specifications. As long as the spring coils don't "stack solid" at full valve opening, a few pounds of difference of "full open" spring pressure or "seat pressure" won't damage a camshaft or affect the performance of the engine. Very few of these old engines get run the way they were designed to do when they were new- - - -wide open throttle for hours on end, at or near maximum horsepower RPM. The way most owners these days drive 'em, the engine is likely to die of boredom, not overwork!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!