@Toxophilite umpteen times, welcome to the forum...I've found all the info I needed to fix my flaring issues here...and on a couple of other forums, but this one in particular was the most helpful, and indispensable for parts
you need to get a pressure gauge from your local hardware store, some 3/16 vinyl tubing and a banjo bolt..from the intake manifold of a junk yard car read this post..
Transmission Modulator Adjustment - Benzworld.org - Mercedes-Benz Discussion Forum
sorry i can't find the post with the pics right now but you really dont need them anyway
I had low pressure, replacing the modulator and the pin was a 30 dollar fix that cured my flaring issue...from 3 to 4, some vcv adjustments took the 2 to 3 from slight to noticeable to not at all...
remember the measurements you see for vacuum and pressure are guidelines or factory settings for a NEW trans, not one with x miles on it so you will have to "tune" your set up...see BC on this forum for if you can disable / eliminate your 3/2 valve from what I understand it only controls the EGR and if you've plugged it you might not need to use the 3/2 valving at all...and might want to sign up for an EGR blockoff kit...search on the forum
IF you do all this and STILL have issues then you might want to look at the Superior kit...I bought one and dont need it now...for now.
Even the local "foreign car" shop that works on old benz's didnt want to rebuild my trans...after two visits while they still wont rebuild my trans if it needs to be done, after seeing that I got it shifting right, the older brother offered to "mentor" me if I needed to bring in a junkyard pull to rebuild....it's pretty cool to fix something and earn respect of pros
good luck and while there are people here who are WAY more experienced and knowledgeable than I am, I surely will do what I can to help you getting your car driving right as well....read read read my brother and dont give up...and dont let anyone tell you that " you need a full rebuild" because you probably dont