I can’t help you with all of it, but some.

Powerglide runs a crossover selector as they shift on the LH side. Trimatic in HG shift on either side depending on whether the car is console or column shift. So you really need the whole HG setup from column through to the box to operate a RH shift Trimatic. Some of the column stuff will be common probably but probably easier to buy a whole setup.

There is a fair bit of stuffing around to get an electric kick down to work, not sure where you could put a switch, maybe use a HG Trimatic linkage and put a switch where the cable attached?

If it was me I’d consider using a VH-VK or WB box with LH shift and putting a free standing B&M shifter on the tunnel. Will only need a few screw holes to mount and a small hole for the shift cable plus just run the small harness under the floor covering.

I can’t recall if the 6cyl Powerglide Speedo cable works with a Trimatic but if not a new cable will be easy. Grab the vacuum line and fittings off a Trimatic car if different to Powerglide.

Pretty certain the flex plate, converter, tailshaft and crossmember are the same. Not sure about the filler tube. Don’t use the old converter, get a rebuilt Trimatic one, they are cheap. Get front, rear, selector and filler tube seals changed when you get the Trimatic serviced - cheap and easy to do before it goes in the car.

Won’t matter today, but HT-HG 6cyl Trimatic cars used the old HK 186 cam. Manual and Powerglide engines used the 186S cam.

All HQ-WB auto other than TH350 have an electric kick down switch on the throttle pedal. TH350 and HK-HG Powerglide and Trimatic have a cable kickdown.

I've got myself a trimatic for the HT now. Does anyone know what colour/teeth number speedo drive gear is required? It has 3.36 diff ratio and standard 14" rim/tyre combination.

The gearbox also has a sender on the left rear on the opposite side of the output shaft to the vacuum modulator valve. It looks like a temperature or pressure sender. I can't find any literature on this. Any ideas on what this is?

I was told the gearbox was from an HZ, but can't verify it because all original paint is missing from the ID plate with just the stamped serial number remaining. The whole unit is painted blue including the ID plate which I assume has been done later.

Thanks all.

Switch for the spark control for pollution equipment. Won’t allow vacuum advance unless the box is in top gear.

Thanks HK 1837 and justgm.