gear ratio means what Ring and Pinions you have. Usually when you buy gears it means you just get a front Ring and Pinion and a rear Ring and Pinion. Then you have to get the bearings, races, seals, and shims, pinion nuts, pinion seals, etc...necessary to set up your Ring and Pinions with your ratio choice up in your 3rd members. Yes, 488's are out there. each 3rd member costs around $250 for the parts to set up and then on top of that whatever $ the gear shop charges to set them up.

it is less expensive for you if you already have the 3rd members removed and you just drop them off at the gear shop, then pick them up and install them yourself. rear axle takes about an hour if every thing goes smooth...meaning no problems unforseen, such as in my case where your pinion welds itself to the outer bearing and race and will not come out