I found a clamp that will work for the rigid mount carbs (73-77). It is a 2 inch T clamp. Fastenall part NO. 0427928. It will work for the big body carbs, both old and later style. However, on the later style it is a very tight fit and you will need to bend the T bolt a little more where the threads start. It is also too wide but should work anyway. I tried a 2.5 inch and it is too big. Wanted to tell you all before I forgot as I have not been able to source the oem's.