ECU differences and date codes?

[weaz4200]

What the difference between all the ECU's shown in the pic? All have the same part number but I'm curious on the subtle differences

1) Some had white plastic around the pins and some black?

2) Some have the Chrysler logo stamped and some dont?

3) Different date codes but internally are they all the same?

Also I cant seem to decipher the date codes... which one would be correct for my 74 charger 360?

Thanks.

 

[idrivemopar]

I am going to take a stab at this, but I think the ones with the white collar on the pin connection and also have the Chrysler logo were manufactured from 1980 or later, which in the case of the two in the picture would be the 183rd day of 1980 and 260th day of 1983. The others were manufactured prior to 1980 so two were made in 76, one in 77 and one in 78. Even though these were used from 72 to 76, they were still being made long after those years. I have an ecu that was made in October of 1973, 2763, no Chrysler logo and black collar versus white collar and Chrysler logo would indicate 73 versus 83.. Its a replacement ECU since my car was built in April of 73. This all of course if my logic is correct.

 

[weaz4200]

Gotcha. Did they use the same ECU for points and non points distributor? Or better yet when exactly did they switch from points?

 

[idrivemopar]

Electronic ignition was introduced by Chrysler in 1971 as an option on a couple of models, in 1972 it was available on high performance engines, and by 1973 all models were equipped with it.

 

[Nacho-RT74]

Gotcha. Did they use the same ECU for points and non points distributor? Or better yet when exactly did they switch from points?

ECU system replaces the point system using a diff distributor... point system doesn't require ECU, is a straight relationship with ign coil being a mechanic gate to make shot the coil. The ECU is an amplifier and controler of the ign spark, being triggered by a magnetic impulse inside the distributor, then sending the order to the coil. No more mechanic systems inside the dist.

 

[Nacho-RT74]

And about the ECU dates and look. I think is just about date built and what they decide to make it with what supplier had in stock. Once again, just later replacements. Can't tell if they got upgraded allong the years.

Lot of parts were supplied by 3rd part manufacturers built per Chrysler specs, not really built straight by Chrysler ( same applies for rest of Cars manufacturers ).

 

[ODZKing]

http://www.mmcdetroit.com/Understanding_Date_Codes/

 

[weaz4200]

ECU system replaces the point system using a diff distributor... point system doesn't require ECU

Thanks Nacho.. I wasn't aware.

I think is just about date built and what they decide to make it with what supplier had in stock.

Gotcha. Well ill try to find one with the right date but if I cant swing that then at least I know what they physically look like and it'll at least be the same aesthetically.

ODZKing.. I have already seen the page you linked.. I think what has/had me confused was the break downs for 4 digits...

3301 = 330th day of 1971

This I understand

2995 = Oct 9, 1969

This i dont understand

I wasnt sure which of those 2 they were using to decode the ECU's.