Like Dsaul, I just use some 1/4x.028" tubing, file an oblong hole to get the entry angle the way I want and braze it in. My preference is to put the entry in the DT near the HT on the drive side. I mill out a 1/2" slot in the ST where it's hidden by the DT, and a 1/2" slot in the BB to cover venting for both tubes and to accommodate the cable housing. It makes installation harder than running externally then entering the ST, but I like the clean look.