Making power out of the 318

you're kind of in a tough spot in going from /6 to V8 in that you have to account for all the peripherals (mounts, oil pan, maybe steering, exhaust, cooling, transmission) so it's not just a slam dunk swap.

going to a magnum will likely be cheaper if you're trying to attain a specific HP goal, and will most almost certainly be cheaper if using a 360.

that doesn't mean it's any easier than a standard LA swap, though. there are other considerations: fuel pump, serp belt or v belt set up, flexplate/torque converter, running down a 4bbl intake, exhaust, oil pan.

if you're starting from zero, the magnum makes much more sense and has more potential to make HP cheaply and reasonably, especially so for the 360.