The girdle is not a waste on an RB block. I have the same '72 block that ran without a girdle and you could see the cap squirm when removing the main caps. The girdle takes that away and I have been running near 700hp on the track for nearly 14 years with the same block.
Just curious: are you talking about a 440 or 400 block? Im using the girdle just for additional peace of mind. I installed on a 400 block.
