which catalina 27 for racing?
Buy a boat with an outboard. If it is just for racing don''t even consider the inboard. If you look around there are tall rigs with outboards available.
The inboard boat is much heavier and they sit a little low on the waterline in the rear of the boat. The boat was originally designed for outboard power.
You should join the C27 mailing list here. This topic has been discussed a lot.