ok this might be a stupid question but here we go.......where do i find out what rear end gears i have in my 92 eddie? or did they all come with the same?

there will be a sticker on your driver door with a whole bunch of numbers and stuff. Find your axle code on it and let us know what it is.

axle is d4

limited slip 3.73

well thanks........i have owned the truck for a couple of years but i have never done the rear end fluid or front fluids. it has been parked for 7 mos but i have now got it back on the road again. where i live gets cold.................like 2 days ago the temp was -37c with the wind chill. anyway where i am goin is do you think using synthetics in the rear end and tranny is a good idea? is it hard to do the tranny fluid your self? hehehe might be another stupid one but never know till ya ask i guess lol

cant really hurt, as long as the fluids are compatible with the stock fluids.

i have been using the x for work latley, i am a courier del envelopes, is synthetic the way to go for protection under high stress useage?