Put the big 6 pinion planet in the OD out of a 48RE, add an extra strong spring and a diesel clutch pack with an extra clutch and it will be fine. I block the OD acumulator (the spring is usually broken anyhow)and open the feed passages in the case and VB to apply the OD quicker, seems to make OD go in and out quicker when you hit the button both timing and firmness. No reason chrysler should have let them leave the factory like the piece of crap they were but with minor mods they are very good.
do you have any pics of the feed passage mods ? is the 6 pinion planet a steel case ? i have never been inside a 518, but have been contemplating an ultrabel/518 build for a big block project.
