In another thread I posted that I pulled a 496 with approximately 375 hours. Im having the long block rebuilt. My question: is there anything else I should consider changing while I have access to everything? I hate to drop her back in and not replace a worn paart or two that arent easy to get to!!

Coupler , impellar, depending if housing is scared ? that two.
belt, just a few ideas.

I don't know how your boat is set up with access to your bilge pump. But that is one thing I know I would change. Mine is all the way in back.

X2 on the bilge, cheap insurance. Make sure your float switch is working too.

x3 on the bilge pump. mine is right under my pan. also, clean the hell out of the bildge. you dont want any fallen zip ties or just stuff that falls down into the bilge to clof the new pump. plus it looks really nice when it is all clean.

I would replace the belows, raw water hose through the transom assy, consider changing the shift cable and both the trim sender and trim limit switch. These jobs are a PITA at any other time.

Check the gimbal bearings for play.

Also look at the condition of the bilge pump hoses.