i replaced the fuel pump now it wont start unless i put gas in engine then it run

Did you say Carb? What Carb? Your 1997 Chevrolet truck receives fuel via a fuel injection system, not a carburetor. Either way, if you have no fuel delivery to the engine, check for base fuel pressure with a pressure tester at the fuel rail. Also check to make sure there are no anti-theft system activations stopping fuel supply. If you are unfamiliar with fuel pressure testing, seek professional guidance, as fuel testing can be dangerous.

IF you're willing to share more details it is possible to get some assistance here - otherwise as stated - seek *hands-on* help from qualified personnel.