Question IS your carb a true 950 size or a 750 size bowls?
.... What are you saying here?

I ask this because alot of people don't realize that the 950 is actually smaller than a good 850.
a 750 size would be causing you more trouble.
.... Why would a 750 cause more trouble? It is the tune in the carb not the size that is what the OP needs to address. The process would be the same no matter the CFM.

I would start by enlarging the idle air bleeds and see what your air fuel is at idle i would shoot for 13.0 afr.
then restrict the idle feed to around .028 or.026 and see where you are .
.... I would not start by opening up the IABs. That may have unintended consequences. Start by taking fuel out.

my car used to run like yours and i did this and now i am 12.5 pretty much all the time cruising.
.... If you are cruising at 12.5, you are probably WAY too rich. And there are very real consequences for a cruise that rich.

make sure you are idling on the idle circuit that is a must and most important thing.
I would also start with 84 primary main jet and 90 secondary main.
.... How can you know that when you say that he may not even have a true 950? It is way too early to start messing with the main circuit. You are suggesting too many changes at once. Keep it simple, one change at a time.

jetting affects the whole picture.
.... Leave the mains for later.

You have a A/F so you will see the improvements or not and then know which way to go.
Don't put a very low opening power valve like 4.0. run vac gauge into the car and tape to dash.See what the motor wants. I bet it would be good with a 8.5 opening point that motor needs fuel enrichment asap after you are off the T slot or transition.
measure the size of the pvcr and most likely open to min .070in
.... Again, too many changes at once. Leave the main and enrichment circuits alone until the transitions are close.

the bigger the pvcr the smaller the main jet can be the cleaner the idle will be to a point.
.... No it won't. The IFRs will be somewhere in the .030 range while the mains will be somewhere in the .100 range. How do you see .100 impacting .030?

this is just a suggested starting point you will see real quick if the changes made are improving things,