These are dual springs so break-in will be a snap.
You found a good spring available from Lunati. I have one, too. Both fairly light at under 400# open. These are 190#/500#... sure as hell wouldn't have any valve float to worry about but pretty wimpy compared to what the 1/4 guys run...
Gotta think on this ..... again!
Ordered King bearings this week and they are in at Competition Products. I'll pick them up Monday in Oshkosh. I have to run that way anyway to take my quickchange in to get re-assembled.
