Old style Sure Grip (1964)

I have an 8 3/4 rear in my 67 Dart. The rear is an older pumpkin type 1820657, open rear. If I put the old style Sure Grip, the Dana Power-Lok (# 2881487) from 1964 a clutch type in that pumpkin, is that going to fit? OR will there be issues with axle lengths and or thrust block widths? I'm not sure what year the pumpkin is, if someone can tell me where to find it. Thanks. Chaz.