Lean-Burn Conversion

Duke5A

Well-Known Member
Joined
Apr 6, 2018
Messages
1,661
Reaction score
876
Location
Michigan
The "fun" part will be finding the linkage you need to go from 2 to 4bbl

Edelbrock sells and adapter for the throttle cable and the kickdown can be done by modifying the factory lever. When I did it myself I cut it in half, threaded both ends and used a turn-buckle with jam nuts. Made it longer with the bonus of being able to adjust the kickdown from under the hood.
 

Ele115

Well-Known Member
Joined
Apr 24, 2019
Messages
637
Reaction score
245
Location
Tampa FL
If it doesn't reach, you can make a tiny extension from steel and drill two holes into it. Pretty easy. The kickdown will need to be done right. Do what Duke said, make it adjustable or if there is a gap in the slot put a small bolt and nut in there.
 

AHBguru

Member
Joined
Apr 3, 2024
Messages
14
Reaction score
5
Location
WI
No reason to delete the Lean Burn on a 2bbl car. The computer has a much better timing curve than any aftermarket distributor. Find out the problem - is it the carb, a sensor, a vacuum leak, incorrect carb or timing adjustment, bad timing chain or dampner? Figure it out. You can easily spend $1000 on a delete set-up and never fix the problem.

Test the computer - does timing advance properly when warm? Does the idle solenoid bump up the idle properly? If not, replace the computer. Reman computers are actually cheaper than a delete kit.

On factory 4bbl cars, if it can be proven that the computer is no good, which is rare (they're located up under the dash on squads), they could use a little help in the timing curve. I would order a new/reman distributor for a '88 Dodge 360 pickup, plus the harness and ICU from Napa or Standard. For a carb, find a good late (1980-84) thermoquad for a 318 pickup. You could also use a 17085408 or 17085411 Quadrajet. Stay away from edelbrock and holley junk.
 

Ele115

Well-Known Member
Joined
Apr 24, 2019
Messages
637
Reaction score
245
Location
Tampa FL
My main issue with the 80 Aspen FHP car was it would run too lean. There is a TINY bit of adjustment on the TQ, but not enough. The spark plugs would turn really white. The other issue was the timing advance during first run didn't work, and that's the computer. I have tons of parts and just went with an aluminum intake, 1976 distributor, Holley 600 and a box which I hid. It still looks like it has lean burn but I can tune to my liking in minutes with the holley. I have a couple really good Non Lean burn TQ's I could use, they sound so good but I like how fast you can make changes to the holleys. I would ideally use a spread bore Holley, but they are mechanical secondary 750's so I wouldn't like them
 

AHBguru

Member
Joined
Apr 3, 2024
Messages
14
Reaction score
5
Location
WI
My main issue with the 80 Aspen FHP car was it would run too lean. There is a TINY bit of adjustment on the TQ, but not enough. The spark plugs would turn really white. The other issue was the timing advance during first run didn't work, and that's the computer. I have tons of parts and just went with an aluminum intake, 1976 distributor, Holley 600 and a box which I hid. It still looks like it has lean burn but I can tune to my liking in minutes with the holley. I have a couple really good Non Lean burn TQ's I could use, they sound so good but I like how fast you can make changes to the holleys. I would ideally use a spread bore Holley, but they are mechanical secondary 750's so I wouldn't like them

Lean is always better. That's the whole idea behind the lean burn system. I would always tune mine just to the very edge of a lean miss. That keeps fuel and oil consumption to a minimum, and prolongs the life of the engine. Winter time, I'd have to fatten it up a little bit, but if everything else was in good shape, maybe an eighth or quarter turn out on the mixture screws, at the most. Lean mixtures generally won't leave any deposits on a plug. Sometimes you might see a little discoloration.

If you couldn't adjust it to a happy medium, no matter what engine or carb, that's a good indication of a vacuum leak. I have also had stripped-out mixture screws in a few carbs, too. Then you pretty much have to replace the throttle plate.
 
Back
Top