Good explanation Ronnie. I never noticed they were across from each other on the dizzy.I have always determined them by taking the firing order of any engine (in this case 1,5,3,6,2,4) and arrange the first half of the numbers over the last half (1 over 6, 5 over 3, and 3 over 4 ) to determine companions. I use companions for cylinder balance testing. If an engine is run at high idle firing only on 2 companion cylinders at a time while hooked to a vacuum gauge the reading of each pair can be compared to determine power balance and narrow down a weak cylinder.
Curt B.
