Can anyone help decode Mopar distributor numbers?

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Fishing68

Fishing68

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Need some help.

My car (1968 340 auto) was updated with a Mopar electronic distributor by a previous owner. It has some worn parts (cracked wiring, missing shaft bushing,...) but had been running fine before I broke the bushing during an engine rebuild.

I have another I found for sale in like new condition that I am considering swapping in. I have searched around to try to find a decode source but not having any luck. Looks like people use old parts books to find the application for a given distributor number- I don't have access to them.

Can someone tell me what the application is listed as for a Mopar electronic distributor with part number 3656763 (73)? and also part number 3656587 (72)?

Thanks!
 
Fishing68 said:
Need some help.

My car (1968 340 auto) was updated with a Mopar electronic distributor by a previous owner. It has some worn parts (cracked wiring, missing shaft bushing,...) but had been running fine before I broke the bushing during an engine rebuild.

I have another I found for sale in like new condition that I am considering swapping in. I have searched around to try to find a decode source but not having any luck. Looks like people use old parts books to find the application for a given distributor number- I don't have access to them.

Can someone tell me what the application is listed as for a Mopar electronic distributor with part number 3656763 (73)? and also part number 3656587 (72)?

Thanks!
Click to expand...
3656763 is 73 and 74 318-2 barrel. Automatic or manual transmission. ABC and E bodies.
3656587 is 72 318 2 barrel. Auto transmission. ABC and E bodies.
 
Is there a way easily recognize if one is for a four barrel? ( and is there much difference between the two and four barrel Mopar electronic distributors?)
 
Fishing68 said:
Is there a way easily recognize if one is for a four barrel? ( and is there much difference between the two and four barrel Mopar electronic distributors?)
Click to expand...
It's the advance curve. Nothing you can see unless you have all the specs and can measure. These above are for 2 barrel 318's. There were few 4 barrel Teens.
 
What Mike says. Which leads me to believe that the better solution would be to use either a programmable aftermarket distributor, or a factory 340 points distributor, because that way you could actually get the advance curve correct.
 
Thanks to everyone for responding. I am going to reach out to Halifaxhops and see what he might be able to put together for me using the Mopar / Mopar OEM spec electronic ignition parts.
 
Interesting, I will wait to hear back from Halifaxhops.

In the meantime I had had someone outside FABO chime in on the published application for the Mopar Electronic distributor with the part number 3656763 and they say the Mopar book lists it as for a 340...

Does anyone know if in 1972-73 the 340 engines were paired with 4bbl or 2bbl or both?
 
to my knowledge 340's only came in 4bbl flavor.

(waits for somebody to chime in with a chrysler marine reverse rotation 340 2bbl tugboat application)
 
Fishing68 said:
Interesting, I will wait to hear back from Halifaxhops.

In the meantime I had had someone outside FABO chime in on the published application for the Mopar Electronic distributor with the part number 3656763 and they say the Mopar book lists it as for a 340...

Does anyone know if in 1972-73 the 340 engines were paired with 4bbl or 2bbl or both?
Click to expand...
3656763 is a 73 and 74 318-2 both transmissions, A,B,C, and E body
 
Fishing68 said:
Interesting, I will wait to hear back from Halifaxhops.

In the meantime I had had someone outside FABO chime in on the published application for the Mopar Electronic distributor with the part number 3656763 and they say the Mopar book lists it as for a 340...

Does anyone know if in 1972-73 the 340 engines were paired with 4bbl or 2bbl or both?
Click to expand...
As TMM posted, the 763 came on a 318 2bbl in '73 and '74. A '72 340 came with a 3656278 and a '73 340 came with a 3656771. All 340's those years were thermoquad 4bbl's. The first year for an LA 318 4bbl is 1978. The differences between most of those electronic distributors are the mechanical advance curve, and the throw on the vacuum advance.
 
With today's gasoline, just about all distributors need to be recurved anyway, so, unless you're needing to match a number for show restoration reasons, just rebuild/recurve what you have.
 
If you like the old one, then put on a new nylon or steel bushing.

If the tag is still on the side, its probably not been through a rebuilder and you can look up the advance specifications in the shop manual for that year. From that you can plot the expected timing curve.

In general, a 318 2bbl will have a timing curve that advances quickly in both stages.
While in general a higher rpm engine like the 340 will have an advance that slows more in the second stage.
Smog era distribitors for CAP/CAS have quick and longer advances above idle rpm than earlier non-smogged equivalents. This is to compensate for the retarded initial timing for CAP/CAS.

The way to return to a non-smog curve with magnietic pickup distributor is to weld up the inside of the slots and then you can set the initial timing to pre-smog (10-12 BTDC for a 273 4bbl). I've posted phtotos and diagrams - you'll just have to search for them.
 
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