I just bought a 4X4 86 s-10 blazer and was wanting to lower the gear ratio's and don't know nothin about them. Could someone please tell me how to tell what gear ratio's I have and how to tell which gears I can use.

You can probably decode from the vehicle ID label - usually on the door somewhere with all the paint and trim codes. It should have an axle code. Sometimes there's also a tag on the rear with ratio information on it; sometimes it's a bit coded, though.

LOL