If it is a V-8 engine...the firing order is 1-8-4-3-6-5-7-2.....and all Chevy V-8's have the same firing order....on most of them...the #1 plug wire is located to the right rear of the distributor...at about 11:00 ....if you are looking at the distributor from the front of the truck! Allan stepside
Do you have a HEI cap or the small cap? The number one cylinder should be at the front on the left if I remember right. Craig Hager tech1@chevyduty.com