Setting Timing On a Lean-Burn

[70bigblockdodge]

From a performance standpoint, a standard ignition setup would probably work better.
The lean burn although a novel idea is deeply rooted in emission reduction. The original carburetor is very lean at cruise and idle, WOT is not lean, still targeted for 12.5:1. Your exhaust upgrades make this worse. Advancing your timing will improve the behavior of your engine (to a point), you will have to experiment to see what it likes.
Your lean burn is not a aggressive timing curve (makes for better emissions) modern engines learned to use combustion chamber shape to help and not have to put that much timing in. Anything you can do to put more fuel and timing in, it will respond, again to a point, then it will fall off.
Good luck.

 

[Mr C]

Wow, thank you for letting me know about the box, I did not know that. So, I guess now my goal is to find a new computer or switch to a standard electronic igntion. I wanted to keep the system cause it was original, but I guess it is not. I wonder if a period correct box would improve engine performance

If it's any consolation, I changed my 77 to Mopar Electronic ignition and have never looked back while keeping the look under the hood as stock as possible. Few will notice, and since you've already gone the headers route, it's probably for the best.

 

[70bigblockdodge]

Pretty sure the non cats were only 75-76 400 cid lean burns. 77 up everything got cats.
My 76 Cordoba had no cat.
My Parents 77 Gran Fury wagon with 400 had a cat.

 

[Fred A]

Hey guys,
I am currently working on learning how to set timing while my carb is out with @Dana, and I wanted to check some things with you guys.
1. What does the lean-burn do to timing? I have heard that it retards the timing when you accelerate but are there any other effects?
2. A friend recommended that I advance my timing in order to cure my rough idle/acceleration bog. Does anyone have any recommendations on what to advance it to? My guess is 10-12 degrees btdc.
3. Should I use an inductive timing light?
4. Any general timing tips?

Thanks,
77newyorker440

How did it turn out? Still have the lean burn?