RE: o.s. engine question
That would be me for one, though I live in OR. You race at TRCR? Area 52? Church of Dirt? Yeah, 1/10 is on a big decline. What really sucks is that Peel-It closed. That was my favorite track for winter racing!
You should consider racing the NCT. I realize the races are far away, but you get some of the best competition in the USA! Gary Culp and Taylor Peterson, among others, could A main at just about any national level race.
An 18tz in a ST? Sheesh, I can't control my AD2 with a 12tz. An 18 is nearly incomprehensible! As if anyone could need more power, an RB V12 is ever so slightly more powerful than the tz... IMO of course.