back 2 cylinders not firing on 1991 Isuzu Pickup

Just replaced head gasket and intake manifold gasket. All vacuum lines connected. New plug wires. Back 2 cylinders not firing. Timing set properly.

1 answer 1 comment
Have you checked for fuel injector pulse. Use a noid light, and perform and injector leak down test to rule out injectors.
Thanks for the response but my ole truck is carburated. One thing I thought of is I didn't use any gasket sealer on the intake manifold gasket. So I'm gonna go back and do that and I'll see if that may be it. Re- adjusted all the valves, too.