if you *really* want a V8, then at least that's a convenient way to get all the V8 specific parts for the swap.
but unless it's a commando spec or already hopped up 273 it's not gonna be all that much better than a warmed up slant, and any hot rodding to the early 273 is going to cost more than usual due to the unique heads/intake.
personally i'd spend money toward upgrades-- suspension, brakes, steering, electronic ignition, alternator/wiring updates than a wheezy V8