Planning 318 build for daily driver

Your 318 can do something like I'm doing to mine.
small carter carb. (AVS) or Holley of 600 cfm.
Dual plane intake
Headers and dual exhaust w/2-1/4 pipe.
Heads could posibly use a slight mill and clean up. For a few bucks more, some light work under the valve will help. Not porting mind you. Just a good seat angles.
The cam I'm going with is a mild one from Crane. Advertised specs are 272-284 & , @ .050 I think it was 218/224.
Eh, it's in this thread. Take a peak.
http://www.forabodiesonly.com/mopar/showthread.php?t=10508

With your 302 heads, you should be up on the game. That engine should be a roller cam. I would try and stay with that myself. A roller.

To tell ya the truth, I really do not think he'll need to use bigger valves to grab a nice HP rating. My cam would be the largest I'd go with how he listed everything. A tad smaller for better mileage potentail really.
I'll be porting my heads (302's) next year for fun with this combo.