Engine

Just about impossible. I don't think either of those engine were ever available with fuel injection. Even if they were, engines from a different year use vastly different fuel injection systems. You would need to use the proper throttle body that is matched to the Engine Computer. That throttle body will have to bolt onto the intake manifold which will not match the angle of the heads on an older engine. You'll need injectors that flow at a higher rate for a larger displacement engine. The exhaust manifolds will be different and may not clear the steering column. The 351C is a much heavier engine so you'll need stiffer front springs. Plan on a larger radiator too, and you might not be able to mount the power steering pump, generator, and AC compressor properly.