There are shops that will recondition your old one, but that isn't really smart money spent.

The part number for the reverse-rotation unit is M35820RRRD.  If you want a BLUE distributor cap, the part number is M35820RRBL.  These are a good way to go if you plan on replacing the distributor you currently have.  They don't come cheap...plan on $450 for the distributor and another $50 for plug wires.  Ben Franklin X 5 isn't for the faint of heart.

You can try SummitRacing.com or Jegs.com

JQ

I'll try to answer your questions and ask a few too, then you can decide what you want to do 

1.  You can use a regular distributor like from a car, but it won't be spark protected and you will always have that nagging voice in your head wondering........"Am i gonna blow up myself and anybody who happens to be in the boat with me" at some totally unexpected time

2. No kits, but if the springs and weights are all there and not broken they can be removed and cleaned up. It takes a little finesse to get them out because there's a little clip in the center of the points cam/advance limiter that's not a lot of fun to get out or reinstall.

3  If you don't get the distributor all straightened out with good moving advance weights, verifying distributor bushings good etc, the electronic conversion won't do you any good because you need that advance mechanism working for it to run right

My turn now 

Are you trying to get this running for the first time since you bought it?

Have you looked at/cleaned/replaced the points since I see no mention of them?

How much money do you want to spend? The DUI in your choice of colors for a reverse rotation 351w and new plug wires, (because the new wires you just put on won't plug into the DUI cap) will cost around 500 bucks

You can spend a small amount of money on points related parts and get it running, then get the new distributor at some point or you can fork over the big bucks for a new one now and hope the engine is good and it runs

I almost included that distributor in the previous post but figured I'd see if he was just gonna spend the bucks on a DUI first.

He'd have to change gears but, it'll work with a stock or stock dimension oil pump drive shaft.

It has the longer shaft below the gear area which makes it easier to install the distributor.

He'd need a new cap and a new rotor since it's a screw down cap version and his 85 would have a clip down cap and the parts don't interchange

Some part numbers are 

Cap        Sierra/NAPA   18-5352      

Rotor       Sierra/NAPA   18-5403

Cap and Rotor kit    PCM   173073  or the PCM tuneup kit  173024A that doesn't cost much more than their cap and rotor kit but has points and condenser included

A link in the FAQ thread is sufficient.

Assuming this is the Ebay one, it will work even with the longer shaft below the distributor gear. Like mentioned earlier in this thread, it makes it easier to install the distributor 

Are you saying you have a whole Mallory distributor or just an electronic ignition kit or something?

A part number for your Mallory distributor or kit or whatever would be helpful if you want to find out some information.

Anyone who's name might be familiar to us 'old-timers'?

keno

How is it that the longer shaft on the ebay unit can function properly?  what was the point of the longer shaft? does the end drive the oil pump?  I have not had to replace the one on my boat (88 mc with indmar 351w, I know, cross forum guy here but I can't stay away) which I assume its the same as the pcm version. I was thinking about picking up one of these ebay ones a backup.

Here's a video from skiboatpartsonline.com where Ron runs into just the opposite situation and figures out the short one fits where the longer one used to fit.

It's not the best explanation in the video.

The longer shaft has a deeper hole than the short shaft and the extra length on the end just slides farther down over the oil pump driveshaft.

It gives better deeper shaft engagement and as an added side bonus, at least for me, it's easier to install the distributor because the shaft goes over the oil pump drive shaft earlier while you're trying to get the gears to mesh with each other.

It was a running change Ford made in the later years of the engine.

ahh, video was good.  thanks for the reply.  also, while we are on the subject could you expand on/offer advice on how to remove reinstall this clip you mention above ?

"2. No kits, but if the springs and weights are all there and not broken they can be removed and cleaned up. It takes a little finesse to get them out because there's a little clip in the center of the points cam/advance limiter that's not a lot of fun to get out or reinstall".

You started with a boat that you never had running, put in a new distributor and now it runs, but not too good.

Are you sure you have the timing set at 11 degrees Before TDC and not After TDC which would make for a crappy running engine.

6 or 10 or 11 degrees will all work.

DUI says they have 24 degrees of mechanical advance on top of the initial setting so their recommendation of 11 would give you 35 degrees total.

Numerous people around here on CCF say that they get 20 to 22 degrees and not 24 from their DUI, but if you set it at 11 BTDC you should be good

It could also just as easily be a carburetor issue or a vacuum leak causing the problem 

Look down the carb throat while engine is idling to see if it is dripping.

Another test is to spray carb cleaner around base of carb to check for vacuum leak (it will change RPM if the spray gets sucked in).