Early smallblock motor mounts.

Hey guys. Another question.
Are the early (1964) 273 motor mounts different from the later ones. The originals have one large stud going through them with a large nut on either end. The new ones I got from Rock Auto are smaller and have a stud on one side and two studs on the other and are slightly offset. Not sure what to do here lol.
Thanks for any help.
Wally.
The stock motor mount does not have one double ended stud going all the way through the mount. It has a stud on each side that's welded to a metal plate which is bonded to the rubber between them. There are some truck mounts that seem to work ok, although they don't look like the originals. The advantage to using them, is that you can get some with the safety interlock feature, so, that if they break, the engine won't jump up and damage something.