I'm leaning toward a 1UZ-FE from a 1990 LS400. Stock compression is 9.8:1 and the stock headgaskets hold 20psi. There's a few manual trans bellhousing kits for them to mount anything from a R154, W58, Toploader, T10, or Muncie and more.

I like the idea of a Ford toploader with sequential linkage kit though. Sure it's only a 4 spd, but it's beef, and prolly the only trans that will fit between the engine and the rear subframe I plan to swap in.

Anyway, I gotta finish one project at a time.