LU versus NL.
I personally talked to Art Carr a few times before making my decision as to which unit to get and he recomended i go with the NL unit, i have a 9" NL 3,500 stall on my car and it works wonders, the difference as mentioned before is 200rpm higher at cruise speeds, and lost of about 2 mpg, which i dont care, also Art made a good point, if your making some good power on ur car, your best choice is the NL unit, because with the LU unit there are clucthes bearing and other things that have to spin at great speed this, in term will make ur LU unit clutches life very short , i guess what i am trying to say is, if you drive your GN the way i drive mine ur better off with the NL unit cause it will last longer than the LU unit, just make sure you get a nice trans cooler and you will be a very happy customer.