Most things I've read seem to say the cost to benefit ratio is not there as a lot of these mods ie. exhaust, bore kits, clutch kits, do not make enough improvement for the cost. Since you are repairing anyway, the difference in stock versus upgrades may not be that much difference. But that would raise the question in my mind regarding EFI maps and just making sure you are getting the best performance. Unless you are racing or feel you were under powered before, I would keep things as simple as I could. Major mods can be major problems if you are not real savy and that can cost you riding time. I like to ride. If someone is a little faster. Doesn't bother me.
Do you know what made your motor seize???

 

was loosing power the last few months and burning oil..

 

Big bore kit and tuner after that for your year is big money. Read Albaracing about bbk cam and performance.

RZR 800 camshaft and lifters

The best performing Polaris RZR 800 camshaft available.

teamalbaracing.com