36 is great for 23 with a 2.5l opti 150 and Ttop. What prop are you running?
I got a 1987 175 2.4l powerhead on a 2001 mid section on my 23. I ran a 15 mirage and it'd hit 39/40. 17 enertia can hit 42/43 cruises nice at 32/33mph.
https://www.youtube.com/watch?v=jg7cdv1w1vE