Why did nhra change the cam and valve spring rule in 1985?

[Billy Nees]

Originally Posted by X-TECH MAN

Wouldnt it be smarter to limit RPMs from a stocker with valve spring pressures rather than making everyone run a diaper to contain the oil and flying parts from an over stressed "stocker" engine?

It's got to be a whole lot less expensive to change a set of valve springs than to re-engineer a Stocker so you can fit a diaper or pan on it.
OBTW, in this day and age it's not uncommon for S/G and S/C racers to check their valve spring pressures between time trials and between rounds so what's the big deal getting an NHRA Tech guy to check a few. There are plenty of unexpensive tools in the ND every week to check springs on the engine.