I love 170's and built a really sweet one when gas octane took a nose dive. All but gave it away when I went back to a 273. That guy had no clue what that 170 was. Equallized chambers, head milled .060, Mopar Performance cam, 340 valve springs, High pressure oil pump spring, windage tray, and electronic ignition.
The other problem is slant sixes run forever, so not much demand.
