I'm going to have to get a new battery in my 2008 Tahoe. Looks like it's in a tight location. Any advice on changing it? And a good replacement battery? Thanks

 

You will need to remove the curved brace that is above the battery, you could try to wiggle it out but risk damage and shorting if you do...

You are going to hear plenty about going to an AGM battery... that is up to you and how much you want to spend...

I would go with the a name brand i.e. Interstate, AC Delco... I am not a fan of the Duralast just my opinion...

You will be limited to what will fit...
After you install the new battery and BEFORE you start:

Turn the key to start but do not crank for 1 minute...

The HVAC will go through a "learn" procedure, do not adj any AC settings while it is in learn... if you do you may find that the temp is inaccurate or that one side is hot while the other is cold...

Your throttle body may also go through a brief learn period also, so your idle may be higher after installing the new battery... drive normally preferably with some stop and go traffic...

 

I should also add that it is possible, but may or may not happen that some of your DIC settings may change, i.e. Unlock on first button push, or unlock at key removal etc...
This may depend upon how long you have the battery out...
You will have to reset your clock but your presets should stay...

 

I've been using Sam's Club batteries for years now and have had good luck w/ them. Not sure the AGMs are worth the extra cost in this application unless you have a lot of extra loads like comm. equip or hi-draw audio stuff.