Need help beefing up a staight six

[Gearhead999]

It's a six....they weren't power houses to begin with. 170/200 cu in.

I'd check the timing, if it is a real slug. If it is OK. Get a V-8. I pre purchase a mustang for MANY PEOPLE every month. When I look at a 6 cyl. I always give the lecture...."Are you sure you want a 6 cyl vs. a V-8??" Sometimes the customer is blinded by it's a 1966, not that it is a stick six, no p/s, no a/c, no p/b car. It is a base mustang. Not a comfortable car to drive, especially here in Florida.