You will still need the Lexus transmission. You can use the output from the Taco transmission so it bolts to in your case the Marlin transfer case adapter. I suppose you could use the Taco transmission but you will need the Lexus bellhousing, and I think the input shaft on the pump is longer so you will need it from the Lexus, along with the torque converter. Then I don't know how well the taco transmission will communicate with the Lexus ECM. The bottom line is you will need parts of both transmissions.