I'd be curious as to how it affects oiling on the top half of the motor. Better make sure that all of your lifters, etc are oiling properly/equally as you're essentially breaking the valley up into 3 sections..
No substitute for more beef around the caps, that's where 80% of your problems would be. I ran a girdle on my sportsman block, one thing it did add was the amount of work we had to do to get the pickup and pan to sit properly.