Slant 6 stroker?

Yes, because now you can take advantage of the cylinder head actually made for the 170.
I had a 1965 Valaint with a 170, 4 speed and 3.54:1 gears. While it did not win many races aganst 327 Chevs it would kick the stuffing out of most 6 cylinder Mustangs, 6 Banger Chevy 2 Novas and any Corvair except the Turbo ones.