Way back in my misspent youth in 1960 my friend had a 1947 Plymouth 2 door sedan and put a new Sears rebuilt Chrysler 6 cylinder that came bored 1/16 over.. It had a stromberg carb and split manifold. Sounded good.. Dragging on the old University ave in St.Paul where there were about 30 consecutive stop lites and three lanes we got alongside a 1960 Bonniville and a 1959 Buick. We beat them every time for the whole course. The Pontiac second and the Buick last. The guy driving the Pontiac stopped us to look under the hood. My friend told him it was a stock Plymouth because unless you sit them along side one another they look the same. So anyway using the Chrysler six with slight modification was pretty darn good. I think to install the Chrysler the frame under the balancer had to be notched and something with the radiator. Great days back then. At 73 now Im nearly done restoring my 1946 Plymouth convert. I put in a Chevy 350 with a 350 turbo in but in retro I would have found a Chrysler six and bored it out some and added a couple carbs.