Heads for the 318

check these guys out: http://www.aeroheadracing.com/id6.html
ready to run, unless you havea really cheap machine sop around you can't get your heads redone for these prices:
318 1968-1987 318 A-Engine Heads, 1.88X1.60 Stainless Valves, 67-70cc Open Chamber Design, .509" Lift Springs $399.00
pair

340-360 1968-1987 340-360 A-Engine Assem., 1.88 or 2.02X1.60 Stainless Valves, 67-70cc Open Chamber Design, .509" Lift Springs, 160cc Intake Port Volume $499.00
pair