It has 70k plugs replaced about 20k ago no other known issues...it has a buck under load after the tc is in lock up and you are lugging it...now I even notice it when you start the car and the ac is on you can feel it miss....
No CEL and if driving and it does it if you push down on the gas its fine....someone said remove the metal heat shields over the plug wires....I have NEVER heard of ths...ideas >>
I thought maybe a coil pack but which one ??

You said you replaced the plugs 20k ago(with what kind) and what about the sparkplug wires?

I would pull and check each plug wire for damage and target resisance, and pull and inspect each plug. Kink of hard to diagnose this as a misfire when the CEL is not lit.

By the way, do not pull the aluminum heat shields off the plugs. If the plugs or wires are shorting out to the shields, the shields are not the problem.

I used AC pulgs...didnt chg wires,,,most of the length of the wires is covered with wire loom....im thinking coil pack ?? I tried to check it last night but couldnt get it dark because I cant shut the headlights off when its in gear..

I was thinking about misting it first with water

Like I said, you should pull the wires, inspect them for damage and check each one'* resistance.

what is "target resistance" and how do I test the wires ???

Perhaps one of the other members can provide the correct number, but there is a target resistance per inch of spark plug wire. For example, if the target is 0.8 ohms per inch and you have a 10" wire you should get 8 ohms resistance from end to end. You check it with an inexpensive electrical tester that reads volts, ohms, etc. Set it for ohms and place one lead on each end of the wire.

Does anyone else know what the resistance per inch is supposed to be?

Here ya go....

https://www.gmforum.com/trouble-shoo...-wires-278818/

Keep us informed on what you find.

Ok I just went out and misted everything with water and started the car...I see arching on the rear where the 2 rear wires come near the 02 sensor and whatever that other tube is...so this is probbaly my skip right ??
Is there any good way to route these wires so they dont touch anything ??

Use AC delco wires ??

Replace the wires, problem solved.