I think the 7.25 suregrip unit is the simplest closest to correct choice for your 67 model. 273 S w/904 got those. I wont agree that its "stronger" than any other 7.25. I think its adequate for 273 w/904.
They don't come available often. I've seen 3? 5 at most for sale here during my 10 years.
Good hunting
