That could make sence. I don't bother with the later tq's (the smoggers) because they typically don't have the timed port for vacuum adv, and they tend to be lean (as you mentioned). So the next time I see one, I'll look at the top casting to see if those passages affect the other circuits. Thanks for your input.

My experience, running a late model tq, on a single plane intk, and with a low vacuum cam at idle, will be a real challenge to tune in. Run a lot of initial timing (means the total will have to be limited so that mech adv does not go beyond 35 to 38 degs), and get the earlier tq, if you can (side fuel inlet, with vac adv port, no holes/front pad in the top casting). Then open up the idle feed restrictions 0.002" at a time until the idle mixture screws work. Also, make sure at idle the boosters are not dripping fuel. No more overheating or burning eyes.

An earlier tq running todays unleaded fuel, will idle too lean.