[tim_mc]

I forgot to mention that I checked for 12V on the ignition (pink) wire, which was OK. I tested the coil with my ohmmeter and was getting different readings across the "BAT" and "TACH" leads (should be 0-1 ohm). Here is an awesome HEI troubleshooting guide I used by WIDESIDE72 on this site:
http://67-72chevytrucks.com/vboard/s...d.php?t=645976

I checked the original HEI rotor and cap and it looks OK. The first coil and module swap got it running well, except for the three times it died instantly soon after the change - like someone had turned off the key. At least the engine sounded good and I was only facing a likely module issue. Later that day it ran fine on a couple of longer drives with no issues, but I figured it was only a matter of time before it would completely cut out again.

I would not suspect that a GM HEI only a year old would have been the issue. When I had module failures in the past they would not fire at all. That's what made this a bit trickier to troubleshoot. I'd rather something break completely, so it was a small blessing when it wouldn't fire at all on Sunday.

A few more tips. First pic is how I marked the cap to a mark on the firewall to get the timing close to where it was. The second pic shows the rotor position pointing directly at the rear carb stud so that I knew where the distributor would need to drop in. I had also manually turned the engine to #1 TDC. Taking pics is a good way to keep track of parts and their positions. Here's a pic intake torque sequence from the attached Edelbrock installation sheet.