My .02 on the girdle. I agree, I don't think it does as much as cross bolting. Seems kinda flimsy overall and unless you pin it to the pan rail and some how pin it to the caps everything will still move around in the bolt holes. Kinda like Keith says, it will hold the parts together so you can remove the blown up motor from the car. Oh, I remember those SBF girdles using 10-32 SHCS holding the valley together>>>LOL!!!!
I did my own machining on my old 428 block to install 427 caps using our big G&L horizontal mill at work. Worked out pretty easily with stock caps as then you only have to fit the bushings individually. Mine worked well for 20 yrs and is still okay after putting a sleeve in it from last summer. It's wrapped up waiting on its next use. If it wasn't 3/4 filled, I put it together for my blower car.
I kinda cringe at the Program caps as you really have to watch your block machining to get the proper fit between the rails. No fudge work allowed, you have to be dead on. My thought was to eliminate that was to cut the caps and install spacers like a stock cap. In this manner, it loosens the machining tolerance on the block, giving us part time machining hacks some leeway.
I too have seen more power put through 2 bolt caps, but mine only went one season before there was fretting on the mating surfaces, and that is when I installed the cross bolt caps and eliminated that issue for 2 decades of racing that block.