Is there a A/F mixture screw on a lean burn 1945?

Yes. Although there is usually an upper limit to the amount of fuel it will let in. The lean burn carbs usually had a set amount of fuel that the idle circuit would allow in and the "mixture screw" controlled nothing but the air, and even that was capped at a certain amount.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

Next question.How deep in the hole is the screw head? The p.o. removed the plug to get to it,but for the life of me I can't see or feel a screw head.

It could be a allen head screw or a torx head screw. Don't just look for a Phillips head. The screw head is deeper than you think. The last time I had to clear out a concealment plug on a Holley 1945 the hole was 2-3 inches deep.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

Thanks Reed.I was so afraid that it was broken off and was out of luck.

One of the Holley 1945s I have is off of a mid 80s slant and I have to use a small allen wrench to adjust the mixture. The head of the mixture screw is very deep into the base of the carb.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

I'll try one on mine.It is an 87.