The problem can be in the "improvements".

I had the XT front derailleur. It touched the middle chain ring with its bottom part when I tried to mount it 1-2mm above the big 42t chain ring. I had to mount it higher, then it rubbed when I used half of the rear cogs.

The truth is you need a front derailleur that was made for your crankset chain ring teeth numbers.

Also, if the SRAM X.7 shifters were twist ones, they have the micro-adjusting feature that allows to move the front derailleur a little bit to avoid chain rubbing.