I built my 304 for torque, did a 3 angle valve job, an Engle racing cam (they have a couple AMC specific grinds that have VERY good low end torque) a lot of cams for AMC's tend to be small block chevy grinds on a different blank. Edelbrock performer intake and 600cfm carb (smaller carb will help with throttle response and low end power, 600 is plenty for a 360) Stock heads flow pretty well the way they are and actually have pretty good ports, so if you do anything other than a valve job, maybe gasket match them and look for some undercut valves. Stock manifolds or shorty headers and a single exhaust work best for low end torque, long tube headers work well but routing the exhaust can be a pain and you don't gain anything. A single exhaust is actually better here.
Definately upgrade the ignition, the HEI setup works very well and making it fit with the power steering pump is as simple as getting a slightly longer belt so you can swing the pump to the side a little more.
http://www.englecams.com/downloads/2010_engle_catalog.pdf
I used a cam similar to their 5014H, It had lift numbers closer to the 5052H but without the longer duration. 112* LSA also helps give these motors a fairly large and flat torque curve. I started with a performer grind when I did my rebuild with a 110* LSA and never did really like how it ran for me. Going to the 112* with a little more lift made a night and day difference in my engine. (kinda backwards from normal thinking) I ended up with a much better idle which helped with trail riding and tip-in throttle response a lot.
