ECU question and Which ECU to use?

What is the cause for an ECU to start dripping or melting the sealant? And what is a good replacement unit? Napa? Mopar performance? Revnator? Car in question is bone stock survivor 73 RR 400 4 speed.

First Pete I want to see the car since I think you recently chased after it!! Next question at hand, I have seen some real questionable MP stuff so I would avoid.
From time to time good NOS stuff pops up on Ebay.

I highly recommend the Rev an Nator, use it in my Satellite and it works like a champ with their coil.
Also it has a rev limiter which would come in handy with a 4 speed missed shift.

I camouflaged it with a Chrysler Electronic sticker and a dry transfer from ECS for the coil.
Ron

I also highly recommend the rev-n-ator, however it is pricey and may not be "necessary" in bone stock vehicle. I also agree with rjs in regards to avoiding some of the MP boxes, unfortunately, because I always like sticking with Mopar stuff whenever possible.

I bought this box for my '79 Power Wagon from Ehrenberg off Ebay for about $32 ish.

Jegs has it too. Made in USA and more reliable than the MP Orange Box. With shipping, I don't know whose is less expensive.

https://www.ebay.com/itm/JEGS-40805-HiRev-7500-0174-Ignition-Control-Unit/401591552120?

Btw, rjs, that's a beautiful stock looking 440!!!!

Thank you for the compliment but you failed the test!!!

It's actually a 400 with a stroker kit and aluminum heads.
512 10.5 compression pumpgas. The headers and 3" exhaust is the real tell-tail!
Ron

thank you for the replies. I have no pictures of the car.im doing some work on the car for the owner who wants some things fixed on it for a prospective buyer that pointed out the previously mentioned issue with the ECU. the car is not advertised it was by word of mouth by a mutual friend.he does not want picture of the car out there in www land

OK be like that!!! LOL
Also for very correct looking but wrong date I believe Bill Rolik is still selling NOS with I think 71 dates on them.
Ron

Bill rolik??

I've also got a revnator and like it a lot. Don't count on their HP increase claim, but its a solid unit, limiter works fine, and I did notice less pinging which allowed me to up initial timing and get more bottom end that way. Old MP orange box (early 90s unit) lives in the glove box now as a back up.

I had that melting happen to me on an MP box about 25 years ago. It was an otherwise stock 383 Road Runner street car, with the MP ignition kit installed.
Never found a problem with anything but the thing oozing, replaced it with another (newer) ECU and no further problems.
Thankfully the mess cleaned off without issue.
I heard it was a bad batch of the potting material. I've used other parts-store ECUs on a couple other street cars, didn't have a problem.

Geez! Even have a 400 sticker on air cleaner! I'm getting old lol. Even better actually, a stroked 400. Beautiful!

http://billrolikenterprises.com/

Two reasons I have found to the backing potting dripping!

-Age
-overheating due lack of power coming from alternator.