What is the best way to check vacumn on the intake port or on the carb. It is and auto car so should it be idling in neutral or in gear when checking the vacumn?

Thanks Moparts

Definately in gear.
I play it safe by leaving it in R with the rear bumper pressing against an immovable object (e.g. a very large oak tree). My wife doesn't count.

Why do you do it in gear? Iv'e always done it in park or neutral.

yea..why in gear??

I do it in N or park also

and on full vac port at the carb

Its the way I learned it 40 years ago and it always worked well for me.

Plus I like an ultra smooth idle....

because idle RPM always drops in gear?

Mixture is different when in gear on an auto. Always tune the idle in gear.

In the Fall, I changed out my IFR's and needed to retune my N & In D vacuum readings. I started out in N with the engine at running temp and got the best/steadiest vacuum reading and the four metering screws were out 1 full turn + 1/12 of a turn (11:00 position). Then I put the car in D with the emergency brake applied and retuned for best In D readings and ended up with all four metering screws out 1-1/4 turns (9:00).
The motor is under a load when it is in D with the foot on the brake (stop lights/sigs, etc.) which is a normal driving condition. Plus when you tune an auto car in D with brake applied, you will have better and cleaner idle and the off idle response should be better as long as you tune the accel pump circuit too. If the engine is just tuned in N, than there is a good chance that the In D foot on the brake condition will be lean and cause more off idle issues.
In my case, each of my metering screws ended up being 1/4 turn out farther In D than they were when the car was tuned in N (Note: this was in the cooler Fall weather, Summer may only be an additional 3/16 to 1/8 turn out). Once you tune it this way you will need to put the car back in N to recheck the idle rpms to make sure that they are not too high. Tuning the engine for best In D vacuum should lower the rpm drop from N to In D too. A 125-150rpm drop can be achieved.
When you are tuning the vacuum reading In D, aim for the highest vacuum reading at your required rpm level while getting the vacuum needle to move slow and steady. If you can not achieve a slow and steady vacuum reading, increase initial timing and tune again.
Once the metering screws are all out evenly at one turn (or 1-1/2 turns or the range that you think your carb should be), I then turn one of them 1/8 turn outward. If the vacuum goes up then I know that richer is the correct adjustment. Then I move that same metering screw back to 1 full turn and then I start the process of going around the carb twice while adjusting the metering screws 1/12 of a turn at a time and after each 1/12 turn, I wait 30 seconds or so until I reference the new vacuum reading. I also start out with the metering screws out evenly at 1 turn each and I apply a mark (with a permanent marker) at the 12:00 position of each metering screw. This way as you turn the metering screws, you have a visual reference point of all of the metering screws. Because once you are done, you want all of the screws turned out the same amount.
I am a huge fan of tuning an auto car in D. I have had five carbs on this engine and I have tuned each one in this manner to get the best driving results for each carb style.

Hummm?

I will go give it a shot

never had any issues with mine and I only drop maybe 200 rpms in drive from N

idles about 750-800 in drive maybe 850-900 in N

no off idle probs

I can stomp it to the floor sitting in drive and it wont miss a beat,jumps and pulls right to redline

I do feel I am running the timing on the jagged edge though,I can run 93 and it wont ping a bit...run some 87 and it will ping at mid to heavy throttle in traffic

say running 55 and go to pass some one with out stomping it...just mash it a little to go around and it will ping some

but again I may just need to leave it alone as it works good for me right now on the 93 gas

YO7_A66, well written and the way to do it for max drivability and performance.