[fredjacksonsan]

My bro's answer goes with all the above:

"End gap is usuall a ratio using the bore size. The 440 was about .012", but since I had Hyperutectic pistons (high silicon content) the top ring had to be about .027" because the piston tops for those types
of pistons run much hotter.

Piston to bore also is variable but is less that end gap, I'd have to look it up. Ring side clearance is the smallest of the measurements if I remember right. "

I'd go with JDPascal on this one, factory manual is likely to be correct.