I want to use braided lines for the tranny lines, but the only fittings that fit -6an to the tranny are 1/4 npt and get very tight quick while screwing in. I only get one turn or so, and I'm owrried about it cracking the case. Someone has to make the proper fitting?
I do not think the threads in the case are NPT. I believe they are straight thread, with a gasket on the factory fitting.
Your correct, the case is a straight thread, and they in fact do make a fitting that screws right into the factory trans line adapters in the case. I use them in my trans line kits. You will have to find it at an industrial hose dealer, that makes/repairs hydraulic hoses. Aeroquip pn 200001-5-6B