Power Booster Push Rod Adjustment Question

[69LS1SixSpeed]

Question...I have an universal Stainless Power Brake Booster (7"). I need to shorted the push rod on the master cylinder mount side. Currently, it's about a 3/16 inch too long which is pre-loading my master cylinder. Attached is a picture of the booster. It has a small nut and then a larger right behind. I tried turning it both directions but it didn't seem to change the depth of the end of the rod. I tried placing a couple on washers on the bolts to move the master farther away but I don't like that approach. Are these booster push rods adjustable? Inside on the back side of the booster is a threaded 3/8 bolt with a nut that I attached the clevis rod and it seems to be adjusted correctly. Please advise and thanks in advance for your input.

[Madspeed]

What happens when you dissconnect the rod to the pedal?
does it release then?
If not I wouldcall the company you got the booster from
Better yet send it back get your money back and use no booster at all.

BTW is that a stock pedal assy? if it is . Is that booster tilted upwards? it should be.
there are 2 holes in your brake pedal one is high for non booster and one lower for power booster aplications

If that booster is mounted level and you have it attatched to the upper hole you are going to get one Hell of a surprise when you first apply the brake
Its going to suck the pedal to the floor and you will be licking the windshield