First of all you should do your own oil changes (save the reciepts) and I would switch over to synthetics, I use Mobil 1 15w-50? (red cap), I can't find some of the other oils people on this site recommend up here in AK. I change my oil every 3,000 miles, which I guess is a little much when using synthetics, but it won't do anything but good.
I would switch all your other fluids to synthetics also (transmission/transfer case/differentials) people reccomend stuff called Royal Purple, but I can't find that here either. Do a search on "fluids","Royal Purple", and "Mobil 1" and I'm sure you will find what you want.
2001 Ironman Daily Driver... 3.5" suspension lift (OME912 springs and 1" spring spacer), ball joint flip, 1.5" front diff. drop, 33"x12.5 TrXus MT, 16x10 Eagle Alloy rims, Interceptor, PV muffler, K&N air filter, Alpine Supercharger, Bilstein shocks, and some trimming.
2000 Ironman Project LS-1 VX... very slow progress but someday....... ohhhhh someday......