Chevrolet Repair: 89 gmc pickup 5.7, pvc valve, gmc pickup

Question
how difficult is it to change the fuel injectors on this truck? they sound like they are "clicking" the truck runs
really rough and the check engine light comes on after about 6 miles. after the engine warms up to temp. the truck starts to "lope" while going down the road. it will die at stops as well unless i keep giving it some gas.
replaced oxigen sensor and pvc(?) valve..

Answer
lets see...89 5.7, that should be throttle body injected. injectors should be on the top, with two connectors, and some torx bits. disconnect the injector connectors, and take the torx bit screws off. the injectors should just pull out. but i  wouldnt do that just yet. your ses light is comming on, for a couple of bucks, you can go to a parts store and get an obd 1 code puller. get the code, and let me know. if you have a surge at 50, i cant be sure its the fuel delivery causing the problem. it could be anything from that, to a partially restricted cat, to something simple as a very dirty air filter, or pcv valve. let me know. you could probably even get it scanned at a parts store, or a dealership.