318 or 360?

Here the thing if you didn't care about power in the least then I'd say just go 318 4bbl duals and a good tune.

I know power ain't an over concern of yours but a Magnum 5.9l with stock cam 4bbl and headers makes 320 hp @ 4400 rpm very street friendly and powerful, still would make 300 hp with exhaust manifolds.

Do the same thing to that LA318 stock cam 4bbl and headers and I doubt you'd even make 200 hp, even if it made 220 hp thats 100 hp less for the same cost, sure you could add a cam, even a very aggressive cam wouldn't match the 5.9l Hp. plus you could add a cam to the 5.9l and still have 100 hp more than similar LA318.

Never seen a Magnum 5.2l dyno'd but I'm sure it would match the 5.9l or at least make 300 hp.