All 7 1/4 rears the same?

actually there is a difference in the early 7.25 gears and case i had a 1963 7.25 and tried to swap the gears into a 1972 case wouldnt work, but if you have everything complete to swap in should be no problem, i ran a 7.25 suregrip on my dart beat the crap out of it strong as hell behind a v8 4 speed 318.