Thanks Innuendo.

Spent a bit more time on the van today...didn't get as far as i wanted, but progress anyway. Was hoping to get it off the hoist and drive it around a little bit, but ended up a bit stuck trying to figure out the 4L60E transmission settings in the Haltech.
Eventually got the speedo signal roughly calibrated, but couldn't work out why the gear indicator wasn't working well. Ended up bringing a software file home to to do a bit of research.

But i did get a bit of a video walk around with the engine idling...
https://photos.app.goo.gl/2curwisva3bbnW6t8