Automatic ransmission compatibility for la smallblock???

I have a 408 stroker I’m building for my 87 d150 and I’m wanting to build somewhat a touring truck out of it. Tube chassis coilovers wide tires etc. I’ve been looking for a 5 or 6 speed auto trans to go in and I’ve had no luck. Preferably looking for something newer and a solid middle between low and high gearing so I can slam through my gears but still somewhat wind them out a little and drive it on the street without any issue. Truck isn’t really gonna be setup for anything over 110 so I just want strong acceleration. I’ve done some research on all the wiring that needs to be done for for the newer style electronically controlled trans to make it work without a computer managed engine but I’ve had no luck finding anything that will either hold up to 700hp or isn’t absolutely overbuilt and geared for towing. I was looking into the 545hre with 5 speed and overdrive. I understand I’ll need a custom bell housing for anything newer but does anyone know anything ab this???
Author: P.oldnumber7