Ray,
53 Merc's with 312 V-8's dropped in or the later 410 Turnpike Cruiser engines with O/D trannys were a hot rodders' dream in the 50-60's in western PA.
There were a couple of old guys up in the hills that had a 1954 coupe and they had a 410 in it and that car would kick the crap out of just about any hot factory car until the GTO and 396 hit the streets. They lost in a 1/4 mile, but nobody could get near them on top end with the O/D and Firestone wide oval tires.
The car was a real sleeper. Kind of a medium blue with black walls and a quiet exhaust, until it was race time and the opened the cut-outs and little side pipes under the front doors.