Cheap 318 build questions

Just want to put a cheap engine together to haul around with in my 70 Sweptline.
I enjoy being cheap and buy as little as possible.
Haven't any experience from 318's so I need some advice.
Truck is a Power Wagon with manual tranny. Want to wake her up a little. Don't want a screamer, just some more grunt.

I have the original 318 coming out today. It barely runs. Checked compression and it has all from 80-90 to 145 psi. I plugged in compressed air and listened for valve leaks but they seemed to be okay. 2bbl carb needs job. Original points ignition.
The other engine is from the late 80's with roller cam and swivel closed chamber heads. Did a leak down test before I took it apart and it has bad leaking valves.
Bores look pretty good (for my purpose). Some home honing and new rings will be needed regardless what block I use.

The original exhaust manifolds will stay on.
I have some LA 4-bbl intakes and a bunch of different carbs.
Will buy new cast iron rings but bearings only if needed.
Hope to be able to use some of the original valve springs.

Are the swivel heads a better choice than original or will the compression ratio be too high?
Summit have cam kits for 120 dollars for the older engine, what cams should I look for for the newer roller cam engine? Or - what block is better?