I have an NP231 from a 6cyl/5spd YJ forsale. It's out of a '93 and has around 85k on it. It has a HD JB Conversions SYE installed, and comes complete with the shifter. Only missing piece is the speedo, since that went into my D300. You can pick those up on ebay for $10. This t-case is a 23 spline model, so it will not work with you 4cyl to my knowledge.
I am asking $400 for it, and will ship wherever your heart desires. I am located in Tigard, OR. The zip code is 97223, and the weight is probably around 70 lbs.
Please e-mail me with any questions at [email protected]