Not sure if you asking about front or rear axle. I don't think it would work on the front , but it works on the rear. Pics of how we did my ch***is , hope it helps
If you mean that silver thing, with the two arms, underneath the plywood buck that your nose will be made on, then you might be talking about an anti-sway-bar, a relational spring between differing ends of the axle, that travels through mounts, or a tube in the ch***is, but is not locked to the ch***is. If it is locked to the ch***is, then yes, it's a torsion bar. In either case, it can go under, or over.
If you are talking about a suspension torsion bar yes it can be over or under the one thing to be certain of is making sure the direction is correct some torsion bars are left and right that refers to the direction of twist of the bar that is allowed if it is wrong it will break I have used torsion bars on my model t for 25 years and they work great I have however seen on a Chrysler car that had two left bars installed and the one on the right broke it was not my car and it was a OT car you have a pretty *****in car in the works I'd like to see more Sent from my iPhone using H.A.M.B.