No. It's likely to be 1"
as it is on the other boats that have the Universal M25XP, but you probably have the M35 engine on your boat. This larger engine MAY have a thicker prop shaft to handle the higher power of that engine (although the shaft on my C-320 with the Yanmar 3GM30 is still only 1"). You will need to wait for a more expert answer than either of us can give.Try to post this question on the C36 IA message board. There's a lot of C-36 gurus over there.SteveAlchemist C-320