Anyone here work on CAT 3600 engines?

Hello all i've got three G3608 engines and one G3606 driving natural gas compressors, I work on and am curious if anyone had a solution I wasn't aware of for barring these over other than a 3/4" ratchet or an electric pipe threader with a modified die. I like the electric pipe threader but geez they are expensive if you get a decent Ridgid. I'm aware of the pneumatic barring motors but they require the removal of your starter or the addition of another starter mounting bracket and of course all the required piping.