Hello, Bob,
Welcome to Stovebolt.com
Assuming you will be installing this in a 1953 truck:
Any high-pressure 235 (and all 261s) can be installed in a 1953 truck and all can use the 1953 transmission.
Use the 1953 clutch-housing and clutch assembly (and starter), too.
Also, use your 1953 water pump, and install a water-pump relocation plate if you use a 1955-2nd series and later 235/261 (link with info is given below).
http://chev235guy.blogspot.com/search/label/Water%20Pump%20Relocation%20AdapterAll truck 235/261 engines had mechanical lifters; and, all 1956 and later 235 car engines used hydraulic lifters.
Canadian Pontiac 261 engines used hydraulic lifters.
If you obtain a 235 that came from a vehicle/car with a Powerglide transmission, a truck pilot bearing (at rear-end of the crankshaft) will be needed.
Keep asking questions. Be sure to give full information on engine/truck in each new post, so we do not have to remember what you are working on.
Good luck,
