351w Broken duraspark 2 distributer in 351w + roller cam

[Nuzzlet 0]

Hi. I was having some weird timing issues with my 351w with a b303 cam in it. I pulled the cap off the distributor and there was a big chunk of magnet flying around, the rotor wiggles, and the vacuum advance doesn't do anything.

The trouble is as it is a roller cam it needs a steel gear (I think .531?), however off the shelf distributors for 351s use cast-iron gears.

The question is, what distributor would yall recommend? Or should I find a used one / get a rebuild kit and just fix the broken parts leaving my working steel gear and shaft intact?

Thank you!

[RPM 1,190]

I bought a used Duraspark set up years ago. Looked at it recently to find broken and worn out parts, so I bought new parts. I know nearly nuttin about Duraspark, but the Duralast Gold distributor at Autozone is a good deal at under $100. I've used one in my points set up, and have one awaiting my Duraspark conversion. 

[1969_Mach1 333]

You can get another Duraspark distributor then change the gear to steel.  However, changing the gear is a little more involved than pressing a new gear on, align the roll pin holes and install the roll pin.  The roll pin holes are randomly drilled.  There are specific dimensions that need to be adhered to from the bottom face of the gear to where the distributor seats in the block.  If those are off, the gear can either grind into the block or ruin the distributor.

I use an MSD Pro Billet distributor in my 351W.  I did have to change the gear to steel.  But it has a smaller diameter and lower profile than the MSD Billet distributor.  The taller height of the MSD Billet distributors will sometimes interfere with air cleaners on 351W motors.  The MSD Billet distributors are taller than stock distributors.  I think (not certain) the MSD Pro Billet distributor is about the same height as a stock distributor.  MSD also offers a Cap-A-Dapt for the Pro Billet distributor so you can install a large style cap and rotor on it.  One good feature about the MSD distributors over an original style distributor is the ease of adjusting the advance curves.

If I had to purchase another distributor again, to save money I might go the Duraspark distributor route and change the gear to steel.  Crane offers vacuum advance spring kits for Duraspark distributors that will give you some advance curve adjustments, but, not nearly as much as with an MSD distributor. On my other project with a 390 that is what I did, Duraspark distributor and an advance kit to recurve it a little.

[EastYorkStang 63]

MSD #8584 is taller then the duraspark unit I took out of my 351W. With the MSD I had to space the carb a half inch higher so my Shaker would fit. 

Using an Edelbrock Torker manifold replicating the stock carb height. 

[1969_Mach1 333]

The MSD Pro Billet 8578 is 11/16" shorter than the MSD Billet 8584 distributor.  But the 8578 has a cast iron gear so a gear swap would be needed.  The Pro Billet 85786 comes with a steel gear.  The height should be the same as the 8578, but, MSD doesn't specify it.