The TR3 has a 'shim' under the right spring, between the diff and the leaf spring (assuming left hand steering). Since it's below the diff, it lowers the car on that side. Supposedly because often, only the driver is in the car, so it would sit level during spirited driving. Here is a picture of the right and left spring, the right one has the added shim.
I don't think it's simple to remove the shim from the spring, but know it's not simple to remove the spring from the diff.