does anyone make high compression pistons for a 170

Very true! Go big or go home when it comes to all out power potential!

I'm glad we agree.

Additionally, the 225 is actually on the smallish side when compared with the Ford six (300 cubic inches) and the G.M. (292 cubes.) The only reason it can be competitive in this area is its apparent ability to withstand high levels of boost without damage. I'm not sure the other two can do that...

The AMC 240/258 motor is an unknown factor to me.... But, I'd bet it's a good one in relation to the strength issue. It comes with a lot bigger valves, to begin with, and ports to match, so not as much boost should be necessary to make significant (500?) horsepower .

I'm wondering whether the OEM fuel injection system could be modified with bigger injectors and a more powerful pump, to get rid of the problematic blow-thru carburetion we use on the slant six... I'm sure it would require a new computer, or at least, tweaking the one it came with...

I went with the slant six because Tom Wolfe and Ryan Patterson had already done it, and Tom was willing to help me with all the specifics... Thanks, Tom!!! And, there were no engine-swap problems to worry about (I REALLY LIKE the Valiant chassis engineering and the 904/A500 transmission package. Makes a sixties Falcon or Chevy II look downright Neanderthal, by comparison!)

Hard to beat a turbocharged slant six, done right!:D