Doe's anyone know if the 4.0L and the 5.2 or 5.9 V8 out of the grands share the same bolt pattern to mount up a tf 999 to?

Not sure about it bolting up or not but I beleive you would have torque converter issuses between the 6 and the V-8 tranny. I would use the tranny from the grand, your transfer will bolt up to it. If you get a tranny from a 90-95 grand, they only have a 3 wire hook up for the computer. These are real easy to set up manually.