Which coil packs should I use?

[MuRCieLaGo]

Hi guys,

Wasting some money on the General Motors car right now.

Trying to pinpoint a bucking issue since years. I'm so tired of it that I just blindly start changing everything now. Got an RX-7 and a Dodge Viper to manage also, I was expecting the ZR-1 to be a reliable nice summer car. I was so wrong, Viper and RX-7 are always on the road and ZR-1 spends most of its time in the garage. Oh well.

-Cam sensor
-o2 sensors
-Spark plugs
-Spark plugs wires
-Fuel pumps

Have all been changed now.

Next are coil packs.

If I just let it run at idle, remove every single wire and see if there is some spark, there's nothing in #6 and light spark in #1. So I'm guessing that's a coil pack issue finally (same coil pack sharing #1 and #6).

I want to order 4 new coil packs at RockAuto but there's the "OEM" ACDelco and the professional one (which is 2$ more expensive).

Is there a difference? Which one is better? Will they be labelled 1-2-3-4-5-6-7-8?

PS: I want the best coil packs.

Thanks!