Converting lean burn to non-lean

Fred A

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Hello, Anyone know what I would need to convert a lean burn Chrysler New Yorker 1978 with 400 engine? What are all the parts needed?
 
Different distributor set up (Dist, ECU, Wiring for it) And a different carb basically. I have the ignitions stuff if needed.
 
In the early 80's I did it to a 360. Unfortunately, I don't remember exactly what I did but I do know it wasn't that hard. The wiring used the same connector and was a direct plug and play.
 
Direct Connection and then Mopar Performance used to sell a kit, complete with distributor, ECU, ballast resistor and harness, that was initially used for converting a points set up to electronic ignition. They also were great at replacing the problematic Lean Burn system. I don't know if you could find one still around somewhere. They were from Ma Mopar and used good parts.
 
The new ones suck, half the time the orange ECU fails and it is all made overseas now find a pre 2000 one when they were still good. Wach out for the DC stuff that says "authorized or replaces."
 
I did it in 1982 to my Dad's 1976 Royal Monaco with a 400 in it. We used the Direct Connection electronic conversion kit. I bought a Carter Strip kit and rebuilt the Thermoquad carburetor with bigger jets, etc, to eliminate the lean condition. It made a very nice performance improvement too.
 
I agree that when they were still made/sold by Chrysler via Direct Connection/Mopar Performance, they were completely OEM in quality and performance. In many cases, they were still using "distributors" in cars, so not hard to built them. As things progressed, they were licensed to be built by "somebody else", but to the orig Chrysler specs and quality. It seems that this was initially true, but I suspect that the OEMs aren't policing these things like they were. OEMs are typically more focused on "current and the future" rather than backward.

Proform got their start in the USA (from what I remember) selling "bling" under hood items. Inexpensive (i.e., more affordable) items that appealed to people who wanted such. Sold at auto supplies, usually. Later, they began selling licensed GM chrome things. Next thing I knew, they were selling other OEM-licensed things for other companies. The bulk of it "off-shore" made. Nothing wrong with "off-shore" per se as along as the quality and durability is there, BUT the OEM standards seemed to disappear, by observation.

Used to be that that MP Electronic Ignition Kit plus an earlier model carburetor were all that was needed. By that time, there were usually only one or two part numbers of reman TQuads that anybody carried, covering a broad number of model years and engine shopsizes. Nothing specific to a 440, 400, 360, or 318 . . . more "one size fits all" in nature. I was always a bit suspect of getting any good performance from them, but they probably worked decently well anyway.

In current times, getting OEM-based kits from @halifaxhops or Rick Ehrenberger's eBay store can be the best ways to do that deal. The orig MP kit was great in that it had all of the factory harnesses to hook things up, with minimal invasion into the vehicle wiring harness. I suspect @halifaxhops and Rick have similar kits now.

As to the replacement carburetor? The visual favorite would be the Holley Street Demon with the phenolic float bowl. That carb is a Holley clone of the orig TQuad with a few exceptions. Of course, it had the GM and Ford oriented throttle hookup, which will need the adapter to use on Chrysler applications. It will bolt to both square bore and spreadbore manifold flanges, with the secondary throttle plate resembling the old Holley 3bbl carb from the late 1960s. In some part numbers, it can have an electric choke.

Of course, the ultimate replacement would be a new self-learning EFI system which can also control spark timing. For which the OEM Lean Burn distributor might work with it, as just a "distributor" rather than having the spark advance calibrations in it? Although more expeensive, that would update the air/fuel delivery to a currently, perfectly modern system, just as the orig Lean Burn was when it was introduced. Of course, by the time you buy the kit, modify the fuel tank or get a specific EFI model (IF available for those cars), it can be past about $4K, which might be close to what the whole car might be worth. Making the carb/ignition changes more financially viable for most people, IF done correctly.

In prior times, when the LB system had issues, some people went to the auto supply and bought a generic reman distributor, made some wiring adjustments, and "called it a day". Unfortunately, such things usually resulted in the car being sold for a fraction of its prior worth, which meant that the later owners usually trashed formerly great cars as a result. Get the KIT!

A side issue was that by the time the middle 1980s happened and the systems started to have issues, few people at the shops understood the system and made poor repair choices, not knowing what they were doing. We got an Aspen wagon in on trade as it was running poorly and the owners were tired of dealing with it. I had a Chilton book which told how to repair the system with a volt ohm meter rather than Chrysler's "Box" pass/fail item. Our used car tech used that book (knowing that the system was controlled by "voltage and resistance") and got it running pretty good with few parts. And it went to the used car auction.

The bad thing is that to do the system replacement "right" costs about the same as hacking something else onto the car (i.e., "wrong"). Might as well spend your money correctly for the best results . . . for yourself AND the CAR.

Take care,
CBODY67
 
I did it in 1982 to my Dad's 1976 Royal Monaco with a 400 in it. We used the Direct Connection electronic conversion kit. I bought a Carter Strip kit and rebuilt the Thermoquad carburetor with bigger jets, etc, to eliminate the lean condition. It made a very nice performance improvement too.
Re-metering the TQuad to an earlier rod/jet combination can be another option for those that know how to do it.
 
Yes I mostly rebuild Mopar distributors to stock specs but can do anything else. Have tons of ignition parts all tested and pre 2000. If needed I can make a clone for your engine. Most LB are locked out.
 
$75. Works like new money on the 318 and 440.

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Carb change to not make it lean air fuel ratio.
Distributor to have advance, vacuum and mechanical, which are both controlled by the box on the air cleaner
 
I did it in 1982 to my Dad's 1976 Royal Monaco with a 400 in it. We used the Direct Connection electronic conversion kit. I bought a Carter Strip kit and rebuilt the Thermoquad carburetor with bigger jets, etc, to eliminate the lean condition. It made a very nice performance improvement too.
Where did you buy from?
 
Don't I need to change the carb?

If your carbs fuel mixture is adjusted by the computer and has a batch of wires attached to it and a couple of solenoids. Yes, definitely.
Or it will run, but not worth the effort to tune it. You will understand when you disassemble the carb.
New 4-barrel 1405/1406 copy carbs and Holley two-barrel copy carbs are about $180.
 
If your carbs fuel mixture is adjusted by the computer and has a batch of wires attached to it and a couple of solenoids. Yes, definitely.
Or it will run, but not worth the effort to tune it. You will understand when you disassemble the carb.
New 4-barrel 1405/1406 copy carbs and Holley two-barrel copy carbs are about $180.
These are new carbs? What make?
 
These are new carbs? What make?

New China, but they work good. eBay/Amazon. Spead bore, square bore. Whatever. Pick your flavor. May need choke and throttle connection kits, probably will.


Or if you need a big block two barrel. Something like this.


Or maybe this for small block.


Search till you find what works for you.
 
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Fred, Hoppy and/or Rick-O have the stuff you need, excepting maybe a carburetor. Get something either NEW or NEWLY REBUILT for carburetors, I bought an electronic ignition conversion kit from Rick-O (Ehrenberg) for my '83 Dodge D150, and found a nice little mid 197-s Holley for the 225 /6 which I drove home from Flagstaff on a gimpy original Lean Burn carb and ignition. I did this for under $400, and that included lots of small stuff add to the cost of the carb and ignition kit.

Whether Hoppy or Rick-O puts your ignition package together for you, they're BOTH excellent, knowledgeable sources of the best parts you can find. The conversion really is quite easy.
 
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