Specs please

A common falicy is that the super six exhaust manifolds have a larger opening. All slant six exhaust manifolds have 1 3/4" outlets.
Milling 0.100" on my 76 head resulted in 39cc chambers and a 9.8:1 compresion ratio (Static compression of 170-175psi). slant pistons are usually .185" down in the cylinders at the top of the stroke.
You do not need shorter push rods after milling 0.100" the adjusters can easily take up the difference.
If I were to do it again I would do as stated above and take 0.050" off of the head and block.
I was able to get a best of 16.35@82 in the 1/4 mile using a 2bbl setup.
the Carter BBD is a very easy to tune carb and a great choice for a slant. you need to look out for worn throttle shaft bushings. I found the v8 BBD to be much more fun than a slant version.
Most gains are to be had by milling for compression, porting the head and adding over sized valves. Remember the slant head was originally designed to flow for 2.8 litres(170ci) not 3.7(225ci), open it up and let it breathe.