I'm looking at possibly changing the gearing in my rear end in a 1998 1500 4x4, my question is will I also have to change the gearing in the front axle? The truck does not have locking differentials. Also any ideas as to how much this might cost me to have done? Or am I better off finding a new rear end

yes you will have to match the front and rear or you will bind up the tranny and t-case.....cost well it depends on who is doing it

Any rough estimates as far as cost? I don't think this is something I can tackle myself and will probably have to take it in to be done.

You do not want to find out what happens when your gears don't match! I have a 2006 Z71 on 35" swampers so I'm saving to re-gear. Depending on your do-it-yourselfness and tools it isnt to hard but time consuming. Being able to drop both axels and tansmission and transfer case is alot of work if you are doing it on your garage floor but I know for a fact it can be done with a few jack stand and a couple jacks. As money goes I've been qouted 1500 for a total of all labour and parts from my friend who runs a transmission shop. it helps, ALOT, I'm assuming you have stock 3.55 so a 4.10 or 4.57 gear would give way more power to the tires but the shift points and speedo would beed to be re-adjusted. I would suggest just asking a transmission shop and see what they say it never asks to walk in and ask. Hope this helps.