ok so i got this 90 YJ from a stock broker in missouri, it has 20xxx miles on a new motor and clutch assembly, 50xxx on a new tranny all new drivertrain as far as u joints and drive shaft, upgraded radiator. nice seat covers and new back seats carpet and center counsle also a Besttop all replaced last year. garage kept and rarely drivein i paid $900 for the YJ.........
Now the question is what can i do to it appearance wise: 4 inchs of lift on 33's is what i want, i want to keep mileage so where to go as far as gears and lockers. is the rear locked from the factory? please give me ideas to make this a nice mud YJ but also a DD
Not bad on the price. If you want to do this once, save up and get a good quality lift kit and don't go cheap. The best kit would probably be the Rubicon Express 4.5" Extreme Duty. With most 4" kits, you're looking at a minimum of lowering the transfer case and a maximum of replacing the transfer case tail cone with a Slip yoke eliminator kit. You could clear 33's with a 2.5" lift and some TJ flares which require liberal curring around the fender openings. (All hidden by the use of TJ flares.) If you were going with a 2.5" kit I'd highly recommend OME's. If you're really adventurous you could check out Alcan Springs and get custom leafs built for your Jeep. They usually cost around $150 each but are built to your Jeeps estimated weight and usage. You'd need to get your own shocks (Go with Bilstein) and U-bolts.
For gears, you will want to go with 4.88's for sure. This should give you use of 5th and keep the performance to stock levels. Gears aren't cheap and install prices vary drastically. The gears will need to be aftermarket since Dana/Spicer never made 4.88's. Superior is the oldest and first. I think Yukon and US Alloy have 4.88's, too.
Oh and most likely, it will not have a Eaton Track-Lok Limited Slip Differential (aka: Posi). Those came as an option to 4.2L's and 4.0L's with the Full size spare option.