The horseshoe mount is the mount that bolts to the front sides, like a horseshoe hung upright as not to let the luck run out. This mount has a single 1/2 or 5/8 bolt on the bottom that bolts through the x-member. The rubber cushions for this type of mount were never reproduced, and are extremely difficult to find.
I believe swapping out the timing plate to be an eazier instalation. The older chevy and gmc 6 cylinders had a timing plate that was bent on the bottom and had 2 studs coming down that bolted through the motor mounts and the crossmember. These motor mounts are readily available.
