Dual Master Cylinder - bore depth

[arbakken]

My 65 C20 had drum/drum manual brakes with the single pot master, so figured I"d swap for a dual and bought a 67 C20 master with a 1 1/8" bore. I bought a 7" dual booster off ebay so I could keep the air cleaner on my 230 I6. It took over a month to get the booster (don't ask) so I got bored and ran the lines and installed the master cylinder. Booster finally showed up, and I learned that there are both shallow and deep bore master cylinders. Mine is deep, but the booster is meant for a shallow.

I see there are spacer plugs that are expensive and take a long time to get here, and since my master requires a wrench to pop the cap on, I'd sorta just like to replace the whole master if I can get one from oreillys for $30. What master do I need? Running a 1 1/8 master without a booster isn't ideal...

Thanks!