Lmao I just now saw this. The comments are hilarious. I was super busy back in those days. The Doug Herbert HEI distributor I originally got back in 2007 was nothing but trouble. First off they sent me a dist for a 351 which had the bigger diameter shaft so it didn’t work. When they finally sent me the correct one for a 302 base it was binding in the shaft and wouldn’t vacuum advance timing or mech advance with rpms. I could set initial timing and ran it that way for awhile before I broke down and just bought a pro form HEI one that I got dialed in on distributor machine back in those days. The pro form was cheaper and has worked all these years but i’m just now starting to fine tune the timing with help of others on here and another thread. It may be 5 years late but that’s my review of the Doug Herbert HEI dist. LoL
I used the factory Duraspark for an 85 Mustang GT in my 77. This was a six cylinder car. Everything plugged right in. Nothing had to be adjusted. It's been doing it's job now flawlessly for 8 years. Has the big EFI type cap on it, which fits snuggly in front of the first carb of my 3x2 setup and clears the oval aircleaner which sits right over it and is reversed so that it clears the firewall behind it.