will this cam fit it 318
A completely stock 318 would more than likely out perform a 318 with that cam.
A big cam only will not make more horsepower... there is more to it than that. I did the big cam deal one time and it only took one time to understand the mistake I made. I have learned however a lot since those days.
There is a difference in just sounding good and performing good.
If you want real performance from your 318 need to jump into these two threads and absorb the info like a sponge.
http://www.forabodiesonly.com/mopar/showthread.php?t=28974
http://www.forabodiesonly.com/mopar/showthread.php?t=19556