i'm not that familiar with vortecs... but if i ran a fixed 25* on a LH0, it would be it's end. 19* is the highest SA at WOT that the factory calibration shows. the L82 would probably handle it though... runs 23* at 2000RPM, up to 25* at 3600.

considering only the change in compression(8.8 vs 9.6), that's backwards of what i would have expected.