I bought one off ebay a few years ago, bolted it in and wired it up no problem.

When I fired the motor everything seemed OK but I noticed the unit "wobbling" slightly. Didn't consider it a problem.

Really liked it! Idled cleaner and had more bottom power due to the fast advance.

Drove the truck around two weeks, then as I was turning in my driveway the engine died.
Shaft broke just below the aluminum housing in the roll pin.


Bought a Proform from Summit, no problems.

 

I have a 351 W and had the EEC III ignition system which included the Duraspark III distributor. In the process of removing all components of the EEC III system I learned the Duraspark III distributor is actually 1/2" longer than virtually every aftermarket distributor on the market. Originally I was simply going to switch over to a Duraspark II distributor and module but as I said, the shaft for that unit and ALL others I could find measured 1/2" shorter. I was very frustrated after having done exhaustive web searches and was ready to give up when I stumbled on the Procomp unit totally by accident. To my knowledge, it's still the only long shaft available as a replacement for the Duraspark III distributor. It's actually available either way upon ordering, I just had to specify the longer shaft. The distributor drive gear is located in the same place on both, my worry was that my oil pump drive shaft wouldn't engage adequately using the standard or,the shorter distributor so for me, the search was on. I took some flack as you probably read in the earlier thread for going away from the Duraspark or DUI set up but he aint driving my rig, doing any mechanical work on it or paying for my parts. Opinions are like you know what, everybody's got one. So far, I'm very happy with the decision I made to go with the Procomp. Good thing too as it was the only one around at the time that would work for my application! It's possible that the market has caught up by now, or I suppose it's possible just the same that there isn't a market for the longer shaft that would support it's manufacture and therefore it's ready availability.

 

As you made mention of your budget 79F -1504X4, I should also mention the unit I bought isn't the $ 40.00 GM style HEI. It sits on the intake at exactly the same height as the stock distributor did. (I read alot of stuff about those GM style distributors having clearance issues with the air cleaner covers). It also uses the Ford style round cap and an external coil. The body is billet which didn't excite me in the least but that's the only way it was offered. I remember paying about $160.00and change including the coil.

 

I was looking at the same set-up, however I've decided to do a hillybilly Duraspark HEI due to everything being available from local suppliers so i can take it back and chuck it at them if need be lol. Thanks for clarifying everything.

 

For sure on that! Good luck with your project.