You need to tell us what truck and what year 235 to get good answers. There are different bell housings and different 235s to take into account. I can only guess you are putting a '55-59 engine into a '53 or older truck. If so you will need to keep the old bell housing. If the later engine has a lip on the timing cover you can drill holes in it. If not you'll have to change it. You'll also have a water pump issue. There are several ways to resolve that.
