I've got a question. In my pickup with a 235cui engine, a lot of oil leaks out on the gearbox side. The following similar seals are currently installed: https://bestgasket.com/rear-main-seals/4519S - Rubber Rear Main Seal What do I have to do so that I can change the two seals? Do you have to dismantle the complete engine and the gearbox for this, or is it enough if I remove the oil pan and the two blocks where the seals are located? Can someone send me detailed instructions so I know how this works?