i have purchased a 1955 GMC panel that appears to be all original. 6cyl, 4 speed and original rear end. Although the engine does turn, I believe my best plan is to convert to a SBC and of course 12 volt. I have several sbc on hand and have installed sbc in a number of vehicles. Question: I need info on the original transmission eg. gear ratios and is it compatible with sbc or will I need an adapter bell housing? Perhaps a NV 3500 trans or other transmission would be easier? Also what is the gear ratio of the original rear end? any advice or comments would be appreciated. This truck is from the west and is in great shape. I plan for it to be a driver and even used to pull a trailer. Thanks.