Knowing the Head casting number doesn't help ID the engine size as that head will go on both the 235 and the 261.
Check the casting number on the engine found on the right (passenger) side down low towards the front. Then find the STAMPED number on the flat machined surface at the distributor. The stamped number may require scraping and a wire brush to see the numbers/letters...tell us what those numbers are.
Mike B
