I remember NHRA using 125 lbs. on the installed height and 300 lbs at .500 lift when I use to race my 1963 415 HP M.W. stocker before NHRA did away with using the stock factory spring loads specs.in their tear downs
![shruggy shruggy](/ubbthreads/images/graemlins/custom/shruggy.gif)
It was the same spec on both M.W. motors in 1963, not the same in 1964. I'm not sure about the 1962 M.W. specs. either
![confused confused](/ubbthreads/images/graemlins/custom/confused.gif)
On any solid lifter cam motor I build now I set the valve springs up on I use from 140 to 160 lbs. on the seats and from 325 to 375 Lbs. opened at what ever the max lift at the valves are minus the lash
![up up](/ubbthreads/images/graemlins/custom/thumbs_up.gif)
Make sure you have between .060 to .100 clearances between coil bind and the valve seals to the keepers or retainers, which ever one is the closest also
![scope scope](/ubbthreads/images/graemlins/custom/scope.gif)