727 issue

As for me and the new manual spool valve, why simply install that without a real shift kit, that is if you don't already have a shift kit installed. There are a lot of shift kit brands and as I mentioned earlier, by the time I had my most favored 727, I had used parts from B&M, Trango and even made some pieces of my own to install in it. Along with other internal mods.
I like the idea of welding a big block bell onto a 518. It wouldn't be that hard to set up. Git tig?
Really don't even need a tig! I used flux coated aluminum rod a few times to repair cracked housings on some GM's it worked well enough for the id10t guy to go out and get stuck in a mud hole and smoke the 700 I built for him without breaking the housing again. I'm up for the challenge of hybridizing a 518 let's do it !