Help needed quickly

I own a 99 4x4 LS, that i reasently had new head gasgets put on. The car now idles rough and has no pick up. the computer showes there is a miss in #1 cilinder.The mechanic says the fuel injector pump is bad.could this be the problem?or is there something i can check easley.any help would be apprecated.

Is the fuel pressure bad/good. Focus on the miss, bad wire, plug? Any codes. you are missing a bunch of info here.

replaced all plugs/wires and a new fuel pump was replaced 2 months ago.. no codes.checked all fuses, all the computer shows is a miss in #1 .that i know of..the truck ran a little rough before the gaskets were replaced.but not like this.looking for a cheaper way out then buying the injector pump

You sure they didn't put a new intake manifold gasket set on? Either way the upper intake gasket is an 8 bolt plastic housing over the injectors - simple to take off and the fuel pressure regulator is on the injector spider (6 injecors come off it one to each cylinder). The fuel pump line is pressurized and the return line flows gas back to the tank. Maybe you have a #1 injector bad,
O-rings, cracked plastic pipe, injector head, etc. Sounds like mech wants to change out the entire injection - easy but not usually required. Finding that going to the Chevy dealer (yes I know) is often a better option now as they see these alllll the time and their rates are often the same or close to others. Oh, check the #1 plug wire with an ohm meter - they may have damaged it during the repair also.