hello 47 chev. i had the same planning to do a few months ago on my 55 first series. i've even gone so far as to have a nice 350 and 4 speed sitting between the frame rails, and the steering modified to fit the engine. but what made me decide what engine to use was to go to some of the major car shows in the area to get an idea of what others were doing to their trucks, and combine the ideas to use on mine.what i came up with was to keep the 6 cylinder idea, but use a 57 235,[mine came with a tired 51 235], use the stock 3 speed transmission,and change to 3;55 rear end gears,front disc brakes on the stock front end, and a dual master cylinder. as you go along you'll get plenty of ideas. some that i just mentioned might fit your situation since you mentioned that you wanted it to appear stock two times.hope this helps. good luck.
