i have a 87 gmc, 2wd pick up, carb,.. i cant get it to start, it has fuel air and spark, just replaced the fuel filter, could it be the jets?

Is the choke working? If yes, with the engine off open the choke and look down the throttle bores then pump the accelerator, you should see 2 streams of gasoline shoot out if not the accelerator pump is bad and the top of the carb has to come off, If the accelerator pump works the engine should fire even if the main and idle jets are plugged. I hope this helps. Take care.

Make sure battery has a full charge and connections all good. Check fuel pressure, with tbi fuel injection, 9--13 psi. Have helper crank it while you check for fuel injector pulse, with tbi, you should be able to see spray pattern. Engine cranking, do you have spark at the plugs? Any applicable trouble codes?