Enlarging holes in frame

[RocketScott]

I'm hooking up my front brakes and replacing all the air lines

There's a bulkhead fitting going through the frame that I can't find a direct replacement for. The hole is 3/4" and the frame is 3/4" thick (double frame)

Would it be stupid to drill it out to 1"? Or, is there a fitting that can go through a 3/4" hole that has 3/8" fittings on both ends?

I went down to the Parker store today and they were no help