The water pump on the 235 engine is a bit longer and mounts lower than the water pump on a 216 engine. This can cause a problem with radiator clearance as well as the fan cooling only the lower half of the radiator. There are several solutions to this problem but the easiest is to purchase a 216 style water pump and adaptor plate which permits it to be mounted in the same position as the earlier engine.
Other solutions involve shortening the 235 water pump shaft, changing pulleys and fans, and moving the radiator forward a bit.
