Need help finding a HEI conversion distributor cap for prestolite

[iboaterlurker5]

Older prestolite distributor, factory female clip on cap is bad I want to switch it out with a HEI (male prongs) compatible cap. I can't seem to find any info on compatible cap sizes. I measured the old cap and it is 3.75" diameter for a Ford 460 V8.

I am willing to use an distributor cap adapter + HEI cap if that works, otherwise just a direct replacement clip on HEI cap would be best.

Distributor Model: prestolite d3jl-12100-g

 

[matt167]

I'm confused.. GM HEI has never been used in a boat. The caps are not marine rated ( ignition protected ).

Ford used male prongs for many years, nearly as long as GM had used the HEI. BUT, there may not be a cap with male prongs to fit your distributor, and it might not make any difference.

 

[iboaterlurker5]

Sorry, I meant just male prongs, not necessarily HEI. I want male prongs because they dont trap water like female ones

 

[matt167]

Sorry, I meant just male prongs, not necessarily HEI. I want male prongs because they dont trap water like female ones

use dielectric grease

 

[Scott Danforth]

HEI is GM's term for their "High-Energy-Ignition" coil-in-cap automotive distributor. truth is, all ignitions are high energy.

however Matt is correct, they were NEVER used in a boat because as they came from GM, they were never tested for SAE 1171, nor were they available without vacuum advance.

as far as caps that fit your prestolite/ford cap. you get what is available.

 

[iboaterlurker5]

HEI is GM's term for their "High-Energy-Ignition" coil-in-cap automotive distributor. truth is, all ignitions are high energy.

however Matt is correct, they were NEVER used in a boat because as they came from GM, they were never tested for SAE 1171, nor were they available without vacuum advance.

as far as caps that fit your prestolite/ford cap. you get what is available.

That is the issue. I can't easily find what I'd available because there is very little info on this distributor. So I have no clue which cap adapters fit.

 

[Scott Danforth]

there may only be one style of distributor cap available. that is it. you get what is available. you most likely do not get to change style of lead connections.

 

[iboaterlurker5]

Ok, rather than trying to find a replacement cap for a possibly worn out distributor that is hard to find parts for, can you recommend a replacement new marine distributor for a ford 460 (male prongs, more updated/current/electric instead of points/etc)? My current setup uses a distributor (counter clockwise) + external ignition coil + ballast resistor.

 

[Lou C]

The Ford 460 was only used by OMC from 1987-1990 IIRC and I don’t know if they were ever converted to electronic as the Ford 351s were. Even so then OMC & Volvo were then using the Prestolite BID electronic system and modules for those are NLA. I’d just stick with points and standard caps. I still have the original Prestolite with points in mine.

 

[Bondo]

Sorry, I meant just male prongs, not necessarily HEI. I want male prongs because they dont trap water like female ones

Ayuh,..... Welcome Aboard,...... It would make more sense to stop the water from gettin' on top of the motor, in the 1st place,......

 

[iboaterlurker5]

Ayuh,..... Welcome Aboard,...... It would make more sense to stop the water from gettin' on top of the motor, in the 1st place,......

Yes of course but older boat, people walk on the engine cover to access the rest of the boat and often wet, some water seeps through between the engine cover opening. The cap just happens to be directly underneath the engine cover gap.

 

[iboaterlurker5]

The Ford 460 was only used by OMC from 1987-1990 IIRC and I don’t know if they were ever converted to electronic as the Ford 351s were. Even so then OMC & Volvo were then using the Prestolite BID electronic system and modules for those are NLA. I’d just stick with points and standard caps. I still have the original Prestolite with points in mine.

The boat is from the early 80s, old jet boat. Custom built. Just looking for a more reliable distributor setup than points or worn outadvance springs/bushings on a distributor that isnt made anymore. The guy who built the boat has been putting Ford 460s and Chevy 350s in them since the last 60s.

 

[Scott Danforth]

Ok, rather than trying to find a replacement cap for a possibly worn out distributor that is hard to find parts for, can you recommend a replacement new marine distributor for a ford 460 (male prongs, more updated/current/electric instead of points/etc)? My current setup uses a distributor (counter clockwise) + external ignition coil + ballast resistor.

Mallory makes a marine ford dizzy, however since Sierra bought the rights to sell Mallory marine dizzys a few years, the price went from $300 to $600. Summit , jegs, etc, can no longer sell the marine dizzys (they are listed on the sites as out of stock)

it would be a YLM-6XX something

if you find a used one on fleabay, you may get a deal. trigger assemblies are cheap, keep one on board as they have been known to burn out when you are miles from the ramp.

 

[matt167]

I had thought I remembered DUI making marine distributors and indeed they do.. Special order through Summit they do list a 460 marine distributor which is a modified HEI however it's $475.. DUI's stuff is among the best you can buy though. The guy started with a small operation modifying Ford Durasparks, and then it blew up into what it is today.

 

[iboaterlurker5]

I had thought I remembered DUI making marine distributors and indeed they do.. Special order through Summit they do list a 460 marine distributor which is a modified HEI however it's $475.. DUI's stuff is among the best you can buy though. The guy started with a small operation modifying Ford Durasparks, and then it blew up into what it is today.

I found the DUI marine ford version but clearly in the specs it shows not coast guard approved?

Ford Marine DUI – Performance Distributors

performancedistributors.com

Is this because they didnt submit it to the coast guard for approval? Also this one seems to have the ignition coil combined all in one unit.

Looking at my wiring diagram. I would assume this type of distributor is wired directly to the 12v battery source rather than going through an external ballast resistor (external ignition coil is completely removed) like my current setup (attached). I would guess I would eliminate the orange wire from the ballast to the ignition coil (run a 12v directly from distributor to battery/12v source but still keep ballast resistor in circuit for alternator/choke) but also where would I hook the tach up? To the distributor somewhere?

Also I selected the 7000rpm one which is the lowest but my boat is never really going to spin more than 5000RPM and I don't see mention of being able to adjust the mechanical advance springs/timings. I probably want to be fully advanced somewhere around 2500-3000rpms. My compression ratio is 8.35:1 .

 

[matt167]

They are GM HEI's.. I read the description and can't find where it says it is NOT USCG compliant.. If you are unsure, just call them. DUI is a real place that is made in the USA.

The mechanical advance springs are off the shelf parts should you actually want them. However, he sells the distributors pre tuned. that is why they are so expensive

 

[iboaterlurker5]

They are GM HEI's.. I read the description and can't find where it says it is NOT USCG compliant.. If you are unsure, just call them. DUI is a real place that is made in the USA.

The mechanical advance springs are off the shelf parts should you actually want them. However, he sells the distributors pre tuned. that is why they are so expensive

Yeah they looked like a good setup but shows this which is weird. I have decided for now to just try to salvage the stock distributor, see if it runs decent enough (found that is has electric ignition instead of points, someone upgraded it). If not I will just replace it. Thank you for your help