Re jet BBD 2-bbl for elevation?

[Teeth & Tires]

Guys,
I have a mostly stock '69 318 in my Barracuda. Mostly stock aside from being bored 30-over.

For all my fiddlin' I still have a pretty rich smelling exhaust. I live between 5 and 6 thousand feet elevation and was thinking I might need smaller jets.

Opinion: do I need smaller jets? I'm unsure of how the overbore affects fuel/air so there's one question.

Otherwise, anyone know what the factory jet size is on these carbs?

 

[Dana67Dart]

I am in the same boat at 5000 ft. My 273 dart was a CA car with CAP. The Factory Service Manual has the jet number for stock and 1 and 2 steps lean. ( jets are not availble so you will have a devil of a time finding any range.)

My carb called for a particular jet (120-310S) stock. I happened to have a set of 2 steps lean jets (120-297S) and figured that would be better than stock.
I put them in and had misfire issues, HC at smog test was 10 times the stock jets. I put the stock jets back in and no more misfire. My research shows there is a condition called lean misfire. I think that is what I had.
So my recommendation is to stick with the stock jets.

One day I will get an air fuel meter and figure it out, but for now i'm gonna be "runni'n a little bit hot to night"

 

[Teeth & Tires]

Thanks for that info. Yeah, I may not actually have a problem. My idle is not the best but main jets wouldn't play a role with that. I've got my idle screws turned in quite a bit but, without a gas analyzer, it's a guessing game.