Idle Rpm High in Park, Low in Drive

Idle Rpm High in Park, Low in Drive

Glad you made progress.

Newolddart said
Obviously still having the issue of high rpm in park and dropping a lot in gear. I guess I’m wondering if this is acceptable, im still missing something or if I should just tune her without vac and leave it?

This is completely up to you. Everyone has a different goals and different views on what is good for their needs.

Newolddart said
I checked my crank and front cover for marks and found some on both. I remarked the crank because it was unreadable. Turned the car over with vac disconnected to check intial and it showed about 26*... really didn’t believe it and figured the crank had been removed. Found tdc for cylinder one, marked it, remarked crank, intial shows around 10* no vac. Makes more sense but again, setting timing this way is new to me.

I'm not really understanding what you did here. You want to take another shot at describing?

One thing I didn't want to get into before, before you had the basics worked out, is the advance curve itself.
But now it may be a good time.
IF your initial measured 26* when then engine was idling at 1200 rpm and
then you measured 10*, but the engine was idling at 800 rpm
this would show that the timing was advancing rapidly between 800 and 1200 rpm.
That would be very normal on Chrysler distributor.
I can't over emphasize how important it is to know the rpm that timing is measured.

Here are two example plots illustrating advance on small block engines. Notice qyuickly advance changes the timing above 800 rpm on the 1971 distributor.

Newolddart said
I tune the carb for highest vac at about 15” and she idles choppy but nice at about 1000-1100 (afr in park is 12.8-13). In gear she drops to 850ish still idles beautifully (afr 13-14).

Tune for the most power in gear. That is the least drop in rpm when placed in gear and or the highest vacuum in gear as long as the rpm kept the same. Can't use vacuum as a comparison between two different rpms. The engine naturally makes more horsepower as rpm increases.

Newolddart said
I reconnect vac, in park she jumps to 25* intial and about 1500rpm. In gear she still drops to about 850 but runs. This is with full manifold vac. My carb does not have a port vac provision.

Do you know what carb? Does it still have a choke tower?

edit
[and I agree with Crackedback. For now the vac advance is distraction. If it was needed to crutch the situation that would be different. That may still prove to be the case if your tuning points that way and you dont want to mess with the distributor advance mechanism. No need to jump the gun. ]