I was just test fitting the speed pro rings for my 360 and something doesn't seem right. I'm getting 0.016-0.017 gap for the top rings, 0.018-0.019 for the second and between 0.027-0.028 for the oil rings. The 1st and 2nd rings are on the tight side no? These are not supposed to be file fit.

The big thing I see is the oil expander, it has these clear plastic inserts at the each end of the gap I've never seen before. And it has to be forced into the bore, with the ends butted tight to each other. The old expander rings have a good size gap when in the bore.

These are moly rings, part number is E251K and they are the marked for the right bore size. (0.040 over) I'm almost sure this is the same part # ring set I used when I put the motor together originally in '03, but what's in the box is different.

I'm assuming these ain't KB pistons (which have a different top ring gap requirement). I go .004" gap per inch of bore on the top ring and .003" per inch of bore on the 2nd ring. There's a new school of though that you want a larger gap on the 2nd ring to let trapped gasses escape but I go with what has worked for decades. That's typical that oil ring expanders need to be compressed but most are too tight as is & can stand to be crimped to reduce their circumference dimention (within reason) to reduce ring drag

No the pistons are Speed pro H116CP.
I don't know why I even bothered to re-ring it, there was nothing wrong with the old ones.

The plastic pieces are to prevent the expander ends from overlapping, but I found several people on other forums also wondering if these oil rings are too tight. When assembled on a piston the rings can't really move around in the ring land at all.

Any issues with lightly filing rings that aren't meant to be file fit?

the 3 piece oil ring assy does not need to move. yes the colored plastic end pieces need to be butted together not overlapped. Your compression ring gaps are fine & do not need to be filed. You would not want to file anything on the 3 piece oil ring assy. If ever needed you can file any compression ring file fit or not to increase it's gap if needed just keep the ends square & when done lightly deburr the ends with a whetstone or fine file

For your combo you have no problems,you can remove the plastic if you like but the gaps sound normal.The most important details are how round are the bores,is the finish correct,not the gaps.

I just can't see how these aren't gonna tear up the cylinder walls. You cannot compress the oil ring package by hand at all. I see other people have had the same concern so I guess that's the way the speed pro rings are.

On any engine I've ever done before the oil rings had roughly the same tension as the other rings.

get a pair of pliers & make some notches in the serrated end to fit your work & crimp the expander "waves" to shorten them

put all the pistons in the motor without any rings on it and roll it over, then do the same thing with the oil rings on the pistons, then you'll know how much drag they create. If its excessive look for a solution, if not run it.