[cbr900racer77]

I wish I was done with my XX conversion. I'd buy it if I was. I think my next project will be to stick a 1KRR engine in a 900RR frame (I have a 93 RR frame just laying around). As for price, I bought an 06 1000RR engine for a buddy off ebay for 250 bucks. It had been in an accident and case had big crack in it behind clutch cover.

 

[cbr900racer77]

do you just tig up your cases or replace them?

Depends on where the crack is. If it's near bearings I wouldn't bother due to distortion from the welding.