Just adding a 2 bbl to the 170, will not get you a lot, but doesn't take a lot, either. Are you running a standard trans, or an automatic. Putting a 72 engine in front of a 63 trans, has some issues.
Personally, if it were me, and the 170 was in good condition, I would mill the head, to get a true (about) 8.5-1 CR, add the 2 bbl, and open up the exhaust (single). If you want to spend a little more money, a mild cam, and consider (optional) a little bowl porting, and back cut the valves (while the head is off). The rest is tuning.
PS: Convert to electronic ign. I like the GM HEI conversion, or the pertronics. Not a fan of the Mopar system.
