Nope, late ball joints don't fit early spindles. And the early ball joints come in two flavors- disc and drum; you didn't say which one you're dealing with. They both have the same bolt hole spacing, but the disc ball joints have a larger hole- people commonly drill out the drum joints to the disc size. Search to find the exact hole sizes.
1965 PLYMOUTH BARRACUDA 4.5L 273cid V8 Ball Joint | RockAuto
