buying a mid-late 90's chevy truck

I am getting ready to buy a mid-late 90's 4x4 truck to tow a bass boat and for hunting. Any known issues or questions that should be asked? Any help would be greatly appreciated.

Take a look at the inside of the oil cap and see if you see and Orange residue. This would indicate a Air Intake Manifold seal gone bad. Found that on a couple trucks I was looking at before I bought mine 3yrs ago. That is a very common repair on these vehicles. How many miles are on the truck? What options are you looking at? 4x4? Z-71? K1500, K2500, k3500. I assume you are looking at vehicles with the 5.7L Vortech Motor. Otherwise these are great vehicles. My parents had a Tahoe with 375k before it was totaled. My 98' 2 Door Z-71 Tahoe with 158k is still pulling strong.

I don't have a specific vehicle. I'm looking at different ones. It will definietly have the bigger engine, and also at least a crew cab. Thanks for the help.