Easy and a bolt in but depending on the year of the 235 there is water pump issues,55 to 62 motors have a longer water pump that is lower in the block. Shortened pumps are available and there is a adapter to mount a 54 on back pump to the 55 to 62 motor which I am using on the 57 235 in my 37,a 54 motor is a direct bolt in since it has the older water pump.
