HOW ABOUT A 1979 318 V-8 IN MY '73 SCAMP?

^^^ Yes make a plan and stay. Same way IF you try to build any engine, have a good plan for your intended use and stay.
Like said, IF you change to a v8 from that slant, you will need a v8 K, NO ONE is making the conversions brackets right?
Used radiator, crap shoot
That engine from the boneyard, can't hear it run?? Consider it a core ,unless are lucky maybe.
Can only get on puter at work? Go to library and read on here about making reasonable cheap power fro a 318. Look up Willrun318 here.
I assume the slant rurns/drives, IF so drive it while yo get the needed pats to make the change over.
Make it safe, brakes, suspension, wiring, tires etc. Figure our budget it all ads up!!
You can do it, YOU are an OKIE right!!? You ain't from Nova Scotia or some place?? Right!?? lol