...
Thickness has no bearing on the effect of the girdle, as it's intention is to eliminate "flag-pole" esk wiggle of the main studs, which attribute to cap walk and reverberation through the block eventually leading to cracks. It is NOT designed to influence lateral twisting of the block itself.
You're the only other person I know who has ever put it that way, and it's EXACTLY why I decided to use my CRE girdle w/ my fresh 440 block that was already fitted w/ aluminum caps.
The aluminum caps will still act as a "shock absorber", but the girdle should help keep the caps from doing The Wave. I suspect the studs getting moved around when not supported at the top is one of the things that causes that style of cap to crack when used only with main studs.
