Nice truck!

Those cam specs look horrible without boost.

There are a couple bis to set/unset for VSS Drac or Mag so probably be able to run VSS to PCM without DRAC/VSSB, there's no need for signal to speedo on your truck or accurate speed for the E trans so I don't think that is a big issue.

Plumbing, switches and valves for duel tanks is an absolute nightmare and expensive, unless you find a dual tank truck at junk yard for all the parts!

Hidden kill switch is easy and can be done many differant ways.

There is a wire for A/C on and very easy to wire in.

But I don't think that PCM ever had a manual trans? Pretty sure not. You may be better off using the harness and wiring in another ECM? There's so much differant in man to auto bin files.

Hope that get's you started!