A518 transmission

All of the 2WD A500s and A518s I've seen had the same rear mount. It is completely diffeent than all other RWD Torqueflites which used the same rear mount (or at least same location on the trans case). The A500/A518 use a large triangular plate that bolts to the bottom. Scrounge one of these from a junkyard and weld up something to attach it to whatever you are using as a rear crossmember/mount support.