I'm not gonna comment on Apex's tuning skills, however I will say that when I was running a fully modded (SS Spec) 70+hp MC28 I was changing pistons about every 250 miles. I'd put a fresh set in before a race weekend, and then a new set of rings on Saturday night ready for the Sunday warm up and race. A crank saw 1200 miles and then went in my street bike

In the SP class there was less wear on the internals (as less power and rpm) so we would get away with 500 miles to a piston and 2000 miles on a crank (which then went in my street bike ).

Note that all the internals were standard NSR bits, not HRC specials.

In '95 I went the whole season on one F3 transmission, although there was a fair bit of ratio shuffling. In '96 I went through 3 standard NSR transmissions, and my team mate went through two. The standard box is made of finely crafted cheese. HRC made the F3 box....nuff said.