boring my 318

The 318 is a fun little motor that responds well to basic bolt ons. I'd go with 302 heads with a little bowl work, a windage tray , clutch fan, performer intake, headers, x pipe, good free flowing mufflers and exhaust, and a cam matched for your setup.

One thing that I haven't seen posted is what gears are you running?
When I was in high School I had a 318 in a 71 Duster with basic bolt ons and 3.91 posi, it was a great little combo as long as I didn't do much freeway driving, if you do 3.55's might be better. Gears make a huge difference, so if your running some freeway gears your car is always going to feel kinda sluggish around town.

Personally I wouldn't waste money on stroking a 318 though, if you get to that point just go grab a 360.
Good luck with it.