The drivers side bracket, left side of car is incorrectly marked RT from Classic Roadsters and the right side is incorrectly marked LT. See marking in photos.
Nothing ambiguous about that. Posts about the subject are ubiquitous.
Sycraft you might have 2 drivers side brackets. That happened a lot just to keep parts off of the backorder list. It could just be the photo tho.
The passenger bracket should look like bracket on left below.
It’s 3” from center of rear frame bolt hole to the back of the U piece on starter side.
Oil filter, drivers side has 2” from center of the rear frame hole to U piece.
The brackets U piece is 3” wide OD on driver’s side and 3 3/16” on passenger side and the rubber mounts are different too, about 3 1/8” ID on the drivers, 3 1/4” passenger side.
The rubber has moulded numbers to identify it driver or passenger.
Install on opposite sides per CR.
You can cut and move the U piece if it’s a drivers bracket and add washers to make up extra width of rubber passenger motor mount. Lower it 3/4” while your at it on both sides. In photo below passenger bracket is on left side. Long arm of rubber mount goes forward.