[cadillac512]

Russ, the lash isn't great but it isn't the cause of the running problem. It may be a bit noisy on a few valves,but just a bit...can't make it run badly.
As for the spring heights,well, they are quite bad with .100" difference low to high. I need to look up the specs for stock height (can't remember darn it!) but they for sure should be closer than they are,and closer to the higher number than the lower. No spring pressure will sure run badly,but if it has any at all it should crank evenly.


Just looked it up; Spring ht valve closed 2.130" You do have the "long" springs, correct? Not the ones with "rotators" from '52-'53? And the proper retainers to suit?


Are you absolutely certain the plug wires are in the correct firing order? (probably so since that doesn't explain the weird cranking.)
I'd check compression with the throttle blocked wide open and all the plugs out. May be a couple valves not sealing.



Terry