First of all I'm new to this site and to the 4x4 world. Awesome site you got here. I spent 5 hours just reading info and posts last night trying to catch up.(I have a long way to go) Anyway, I just picked up myself an 1985 K5 Blazer 6.2C Diesel. I think it's pretty much stock with 31" tires. I'd like to throw some bigger rubber on it, say around 35" to 37" and I have some questions. I was reading all about the different gear ratios, transmissons and what you need for certain tires sizes. First of all how do I find out what tranny, ratios, etc do I have on my truck. (I know this is a super nebie question) Is there like a big mark somewhere on the hardware or what? Also I want to be able to drive this thing around town and highway as an everyday ride so I'd like to gear it so it can handle normal highway speeds. If I want to put some money into this rig, what would be one of the first and most noticable upgrades that I should make to have the truck. In terms of off road performance. Thanks for all the info and I'll hook up some photos later today.