Yup... Mopar never made anything easy... Personally I'd probably grab one out of a late 80's Diplomat cop car... They had the 360 (cop motor) so they have the 999 with the HD planetaries & I don't remember any cop cars ever having a L/U trans..
Info on the net is all the place, some say all low gear 998/999 are LU, others say not the case...
I worked in a Dodge dealer 82-84, Lock-ups were the absolute bane of the tranny guy...
https://www.moparts.org/Tech/Archive/auto/22.html
Nope...Lock-up convertors prior to using electronic control (which showed up the same time as O/D) was clunky at best... Chrysler had lots of complaints so they dropped it around 84... But even when they were using it, it was spotty... But as long as they were using the super high geared (2.45)...
Thing is Chrysler never made a lower gear set for the 727, So the ones that are made are aftermarket....
By the time you have all the pieces they start at around $700 & if you want heavier duty IE four pinion planetaries or billet the price goes up quickly...
For what you are building a...
Back in the early 90's working at North Bay Ford in Santa Cruz Ford Explorers & Rangers were coming in with leaking rear main seals constantly.... Getting a late model engine out, resealing it & reinstalling it paid 9.2 hrs under warranty... Did enough of them I was getting the job done in about...
That's the beauty or the 904/998/999 Low gear sets are stock in the 998/999... So 82 &l ater model L & M body cars, Most junk yards as well as most transmission shops should be able to provide what you need...
Diplomat/Gran Fury as well as the Chrysler 5th Avenue models are what your looking...
Like I posted earlier, there are options... If you can fabricate you can make someone work.... You say it's not pretty, well when the boot covers it up it looks great...
Sounds like most of you guys want to work of stuff... I just want to drive mine... The more the better... Unfortunately the reality is they always need some kinda work...
Seventeen years... And somehow "It's Back!!!!!"
Since someone else dug it up... Here's a single stage paint job... Pretty decent depth... Car has been done for thirty years now & still looks good...
Another was a 64 Buick Riviera G/S with the dual quad 425.... Engine had been built by a local speed shop but the car sat unfinished for a few years.... Another one that got towed into the shop to get put back together.... Another car I expected to be kinda fast that was seriously...
Bright Orange 71 Pantera.... Worked on it back in 1982, came into the shop for electrical stuff... I was drooling like a fool... When the guy picked it up he offered a ride... Of course I jumped at the offer.... Thing was an absolute PIG......... A few days later I was rolling down the freeway...