I have owned my '91 RRC for almost 15 years. I have used it for green laning and it has been abused but it still keeps going.
Rot repairs should be expected for any RRC. If you can find a reasonably straight one that has been looked after then go for it. However, if you are not able to do repairs and maintenance yourself be careful. Just when you think all is good they can bite. Mine has just had another round of repairs; rear diff pan, fulcrum ball joint, self-leveller ball joints, new spring seats and anti-roll bar brackets. Just waiting on new rear brake calipers and I'm good to go again. I know all that might sound bad but let's face it, the car is almost 30 years old and stuff wears out and rusts which pretty much sums up any motor of that age. Most parts are available but some are now hard to find and a touch expensive.
The V8 engine is quite simple and easy to work on. It is very forgiving and will run when it shouldn't and indeed, not work when it should! Watch out for head gaskets and cooling problems. The V8 doesn't like to run hot. Radiators are very expensive; I had one re-cored not long ago and it was quite pricey because the V8 has a big radiator and the core is no longer a "stock" item and has to be done as a special order or so I was told.
Transmission - well I've not had any issues. The auto box is reliable. Transfer box likewise. If you have one with a viscous coupling instead of a manual diff-lock be aware of viscous coupling failure; the viscous coupling can be changed and isn't that bad a job.
Is it worth it? Oh yesssss. RRC is nice enough to drive, the V8 makes a nice noise (but does like a drink), the heater works, cruise is nice, ABS is good, handles quite well (relatively) and if you get in to the mud or it is snowy and icy there are few better motors to be in.
Hope that helps.
