A GM 4.3 engine is a 350 with the back two cyls missing. Everything on the front is the same.
No one cyl on the cap is at 5 o'clock with 12 o'clock to the firewall. Firing order is 1-6-5-4-3-2. Left bank looking forward is 1-3-5 Right is 2-4-6. Dist turns clockwise.
I have had some problems with that year ignition module. (In the distributer)in that year. The coils are bullet proof. Before you start pulling things apart you might want to invest in a new module, they are cheap. You will need a 5.5 mm socket to get it out of the distributer. Some of the models have a phillps head. Make sure you put the heat sync paste between the distributer plate and the module.
The ECM is a very rare failure one in 10,000. I wouldn't bother with it. Let me know
Good luck
Saturday, April 1st, 2006 AT 7:12 AM