The firing order is 18 43 65 72.
43 2 1
On my Astro, the firing order is located on the distributor cap- Where each plug wire goes into the cap, there is a number on the cap-find#1 go clockwise for the next number etc. That's your firing order
check the knock sensor if that's not it try the electronic spark control moduel
there isn't one.
The correct firing order is 1-8-4-3-6-5-7-2 Look at this diagram. Copy and paste into your browser. http://autorepair.about.com/library/firing_orders/bl-fo-7067.htm If you removed the distributor or turned the cap you're going to need to reset the timing. But anyways, looking at the cap from the front of the car put the wires on in order starting plug #1 just to the right of the six o'clock position. The go clockwise in the firing order 1-8-4-3-6-5-7-2
if your saying your engine is a 4.3 your have a v6 not a v8. even with that I've not seen a Chevy engine with cap in front like a ford or Chrysler product. v8 up until 96 i know for sure are 18436572 I have found that some police package cars with a 4.3 it can be a version of the LT1 motor that does have the distributor in the front. I didn't believe it till I saw one at a police auction. I do not, however, have a firing order for this six banger. I hpoe that this might at least help.
When you lift the engine lid and look at the engine, it should say "Zundfolge" 1432 I believe, all engines for the past 60-70 years have had the firing order embossed or stamped where it is readableon the block, engine case, or cylinder head. My '43 Jeep does, my '70 Ghia does, all other cars do as well.
.43 is the gap
knock sensor
5x115 43 offset
About 43 Lbs.