Slant 6 stroker?

stroke isn't the issue, bore is. I'd try find the thickest block I could and bore it as much as I could.....then there is the restriction of the head.....
boost is your best bet, TBH
A 3.50" bore on a 170 (2.8L) short stroke, 180.4 CI or 2.96L, with a big valve ported head and a turbo pushing 20+ PSI would be fun in a light A body.