I put a 91 4.3 TBI / 700R4 in my neighbor's 89 TJ, YJ, I don't know, but it had a cable-driven speedo. We replaced the speedo with an electronic unit from a later Jeep, and used the DRAC and VSS from the donor. I hooked the speedo to the speedo-output on the DRAC and it worked. Also calibrating the DRAC was straightforward as well, and easier than messing with gears and drive ratio adapters that are so often required on Jeeps with big tires. He had no trouble sourcing an electronic speedo, and it wasn't difficult to swap.