Cheap 318 performance mods.

Weiand Action Plus is a good intake... but so are many other dual plane intakes. IF keeping the coil mounted to the intake, then make sure the intake you use has the bosses for the coil mount.
Many "cheap" head options.. .including using the heads you have. Good valve job and cut them .030 for a slight bump in compression and a good head gasket seal
Keep the cam small ... like 204-212 @ 050, lift around .427-.455.
Add new valve springs with the cam (if you install a cam).
Add a good timing chain set to the list - I have had great luck with the Edelbrock double roller, and it's affordable