I've found a replacement for my 216 with the cracked block in my 46 1/2 ton. It come from a 39 car, with a 3-speed. My truck has the old crashbox 4-speed. Will I need to swap the bell-housings, or are they the same. Also, is it harder or easier to pull (and put back)the motor and tranny together or apart. Any other helpful hints on swapping out this engine and tranny? Thanks!