How close have you run piston to head clearance? Application is steel rods, flattop pistons, and less than 6500 RPM.
Seems most like to see .035-.040" minimum. I've run one at .035" and never had an issue.
Just curious to see if anyone has run them tighter?

CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax