Tony - the 3800 is actually a 1T isn't it? - 3400 is 3/4T
wasn't there some modern swap for the rear on 1T? I think you'd have a hellofa time swappin in 1/2T axles on that frame - more like the 5spd that Jeff suggests, and then a roof vent and onea them neat window mount swamp cooler things from the 50's to happy up the co-pilot
Bill