Stock 318 bolt on performance modifications

Since you have the engine out, or will I would replace the timing chain and as many 40 year old gaskets and seals as possible. Beyond that, let your budget be your guide. If it were me, and I had about $1000 to play with I'd do the following...

Edelbrock Performer intake
Edelbrock 1406 or Holley 1850 carb
Comp XE260 "K kit" (comes with springs and timing set)
Fel-Pro complete gasket set
New freeze plugs
Engine Paint

Dual 2 1/4 exhaust from manifolds or basic 1 5/8 headers(optional). Headers can be added later.

The intake and possibly the carb can easily be had used to save some cash. Should be a great improvement over stock, get good mileage, and have great street manners.