What cam?

moper makes a good suggestion.
I would not use a Edelbrock cam. IMO, you can do better. Edelbrocks advertisment of matched componets is to make things easy for those not knowing alot about matching componets. Though not a bad choice for adding torque, theres better cams to suite the needs. Edelbrocks problem is to walk the thin line of not to much cam but enuff to make a nice improvment.
It's a catering to the mass' thing I think.

I am doing a Duster project now.
http://www.forabodiesonly.com/mopar/showthread.php?t=10508
It is powered by a stock '79, 318. This is a lower compression engine than earlier 318's. The low compresion is a minor problem. But it can be made worse by wrong cam choices.
Whats your gear ratio?

My choice is a Crane cam. It may not have as an aggressive lift as the Comp cams XE line, but it also has a wider centerline @ 112 to help build cylinder pressure. Theres not a big difference in 2*'s of lobe seperation, but every little bit helps.
The current specs are 272/284 advertised duration, (@.050 is 218/224 I believe) with .454/.480 lift. Also Crane springs that are for the cam. The rest of my build up, bolt on parts are a old Edelbrock LD4B (Dual plane) intake and a AVS (Small), headers. 904 trans and a 8-1/4 w/ 3.21 gears.

Later down the road, I will do a light mill of the heads for a better ratio that will work with the cam better. As well as a little prep work on the head.