what would you do? engine swap or make manifold

[jireman]

I have an 76 450sl I just abot have the body work done when I bought it I got a rebuilt engine with it.Itried to sell the egine but the only people who responded were scrammes.
I find the injector system scrary. My car has 80k miles and the original engine is still in the car with the headsoff it. What I am thinking about is eather a ford transplant or taking the head ect. off the rebuilt and putting them on original engine. leaving the injector system off and building a carb manifold. [ low gas pressure and something I can under stand.] are there any hidden electrical mecanisims I need to consider? Could sure use some guidence.
I am an old stock car racer and have built a few cars and bikes. so this Ithink is possible.
Jim