Tracy, I say a lot is being left out, so let's fill in the spaces. If you can, help us oout and get your guy Pat to post here, or maybe try your best to post things he has written in context? Also, since you enjoy the car in heavy traffic, why did you choose to lock your distributor? One last question, what are your leakdown results and what is your threshold of "good" for a street driven motor wiht thousands of miles on it?
Patrick James owns a company called Pro Systems. He builds carbs. and tunes Pro Stock programs as well as other high end race vehicles. Getting him to find time to post on this forum is more than likely not going to happen.
I do not float around the internet looking for things to copy and paste to help support my point of view. I can only give you examples by real experience. That being said everything I posted about what I have done to tune my engine came straight from Patrick James while I was on the phone with him. His phone number is 727-490-5717. He is a super nice guy who has always had the time to help his customers.
Another person that I place faith in is a man named Kirk Jager. If you would like to figure out the mind that this man has, please look at his work with connecting rods.
http://www.google.com/patents/US20040107794
I will admit, I copied and pasted this link so you can know who this guy is. He is a much better tuner than he is a machinist, IMO.
Now, the reason I mentioned all that about these two people is because I was having a problem that sounds quite similar to the one some of the other guys have posted on here. The engine would not run properly with mech. advance in place. Some of the problem was fuel lighting in the pipes. This caused temps in the motor to rise and caused overheating, poor drivability, etc. Playing with different timing curves did nothing to help my problem. Based on Patrick telling me to lock out the dist., I went that route. Kirk backed up what he told me, telling me you can't tune these engines like any run of the mill stocker. He told me that there wasn't enough timing at low rpm to burn the air/fuel package. By locking out the dist. and having 32 degrees timing at low rpm, my problems went away. The engine smoothed out and stopped overheating. Retarded timing can cause fuel to light on the exhaust stroke, therefore you will have glowing pipes.
This is why I enjoy my car in heavy traffic. I don't like overheating, pinging. If you think advanced timing is the only thing that can cause those problems, I would suggest building a high h.p., big cubic inch motor and make it live on the street with your tune up theories. A 4.500 bore size with a rod length of almost 7.00 will pull a ton of fuel and air into a cyl. The longer rod causes the piston to dwell at t.d.c for a longer time, giving the piston more time to pull all it can in. This is why your information will not apply to my motor, and my information may not work for you. But on this subject, you will never me ever saying: My way is the only way, and neither should anyone else.
Leakdown has never showed more than .5 to 1 percent and that was only on two cylinders at the valve side. A quick touch on the seats took care of that problem and it's been 100 percent tight every since.
The only reason I did that was because the motor developed an oil leak at the pan and I had to pull the motor to fix it. Pulled the head, fixed the seats and put it on the dyno again while I had it out. EGT's and AFR's were spot on with the dist. locked out at 32 degrees.
If you have anymore questions, I will be more than happy to answer them.
Tracy