360 heads on a 318 of any benefit?

Best option IMO for a street 318 is a pair of #302 heads with 1.88" intake valves and some porting. 360 heads should only be put on a 318 if you're going to do some massive milling and/or swap to zero-deck pistons and build the engine for high HP and RPM.

The Performer intake works best on the 318 but can be bolted to a 360; mind you it would probably only benefit low-end torque for something like a truck. I also have a factory iron 360 4-bbl. intake and I'm looking for a Performer to put on instead. I haven't run either but the better port match-up and much lighter weight would be big benefits (for me at least) on a 318.

Also unless you really want to spend as little cash as possible you might want to check out a modern fast-ramp cam such as the Comp XE line or Lunati Voodoo line. They might be more expensive than the Summit-brand or old-style repro cams, but the increase in torque and efficiency might pay off.