holley six packs run lean when new?

[70charginglizard]

http://www.allpar.com/mopar/440.html

"Holley is supplying the correct carbs for most '71s, but for both '69 and non-California '70s, they're substituting the '70 California Evaporation Control System (ECS) carbs. This represents absolutely no problem as far as performance is concerned, with one exception: As our carb-specification chart shows, the replacement center carb for the '70 to '71 cars is a bit on the lean side, especially for fresh-air cars. You should, therefore, probably consider rejetting the center carb to stock specs (if not a step or two richer) for your make and model. The bit of extra fuel at cruise can help prevent the lean-surge condition that bothered some of these cars when they were new."

huh.

Now thats interesting.....

[62 Max]

Actually,there are two problems,a lean idle condition is prevelent with the end carbs.Most require an additional 1/8 turn out to correct the problem.# 65 jets in the center will work for just about any combination unless you have a large cam.

[mauve66]

http://www.allpar.com/mopar/440.html

"Holley is supplying the correct carbs for most '71s, but for both '69 and non-California '70s, they're substituting the '70 California Evaporation Control System (ECS) carbs. This represents absolutely no problem as far as performance is concerned, with one exception: As our carb-specification chart shows, the replacement center carb for the '70 to '71 cars is a bit on the lean side, especially for fresh-air cars. You should, therefore, probably consider rejetting the center carb to stock specs (if not a step or two richer) for your make and model. The bit of extra fuel at cruise can help prevent the lean-surge condition that bothered some of these cars when they were new."

huh.

Now thats interesting.....

when i put mine on the '66  383 i used the 71 carbs figuring that it would help the emissions some since i was in Colorado and at the time i thought they would smog it, turned out they only did 69 and later, but mine ran great out of the box with the lightest springs, of course being a slightly smaller engine may have helped as it wasn't using quite as much fuel???