The dished 16cc piston is a bit of a compromise because as Brent said he's considering the possibility of moving to a different set of 64cc heads at a later date. Running this particular piston puts the compression a little on the high side with the small chamber heads and a little on the low side of what I'd consider "optimal" with a set of 64cc heads.  However, the differences between the two compression ratios and “optimal” is minimal when using 93-octane gas.

Yep, Bob, I understand your concern about the oil rings on the long stroke, long rod combos.  I had serious reservations at one time myself and did my best to stay away from support rails when possible until relatively recently.  In fact the 406 engine before last I built for my SS used 5.7 rods due in part to my apprehension on using support rails and to get a thick top and second ring land for the amount of nitrous I planned on using.

I’ve seen comments from well-known engine builders that have said they’ve had no issues regarding support rails – as long as they’re the right ones (you have to check to make sure they put the right rails in the right box). Also, the last few engines I’ve built used rail supports and no one has reported any oil consumption issues.  So, I suspect that if you’re seeing a little higher than normal oil consumption that it probably has little if anything to do with the support rails.

Now, I’ve always been partial to the Napier second rings for their improved oil control over other type second rings (whether using support rails or not). They are a required build criteria for me as opposed to using a different type 2nd ring, so that may be a factor as nothing I've built ever had any oil control issues.

The two ring sets I recommended to Brent both utilize a barrel faced Moly top ring and a Napier second ring.  I’ve used the same series Mahle rings in builds before, but the other set, Hasting rings, look to be better on paper.  I’ve never used Hasting rings, but from what I understand they supply rings to Wiseco and JE for them to put in their boxes. So I asked Brent to consult with his machinist (who is a well known engine builder in his area) to see if he had used and could recommend the Hasting rings over the Mahle.