if the pistons are stock 318 pistons, use mag heads vs. 360 heads. you'll get slightly smaller ports, MORE flow and about a point more compression. use hughes 1110 springs and 2.2L retainers.

rockers will be MUCH cheaper, you can just run chevy stud mounts by either redrilling/tapping the pedestal mount holes, or getting special studs with a 5/16" bottom.

personally I'd run a comp 270H hydraulic if you want flat tappet.