Hey I am doing a 6BT swap into a 86 K10 1/2ton got the motor all figured out that was a snap but now I am putting a turbo 400 behind it that was in a frito lay truck that had a 6BT in it and I was just wondering if any one knew out there if these tranny's need a kickdown cable? This could be my weakest link!!

i think they are vacum kick down? and there might be a cable kit you could put on it, that might be the easest way.
if the trannys off a cummins and you are putting it on a cummins it should of been figured out.

Have you considered the weight? A 6bt is around 1200 lbs, an old 350 V-8 is around 700. Might be a little better as a 4bt, lots of power and potential, and only arond 800 lbs.

The TH400 uses a vacuum modulator to set "throttle pressure" (I guess the frito-lay truck had a vacuum control valve on the throttle linkage to run that) and a kickdown switch to provide a WOT 3-2 downshift. No TV cable.

I've got an '85 silverado 4x4 with a big block I'd have been day dreaming about converting to a 1st gen 5.9. Love to see some photos of the swap.

See thats what I thought to I thought they were vacuum operated but their is no modulator on on the tranny. I also have seen the electric kickdown switch but how and were would it get wired into the tranny? The weight isn't much of a factor had to go with 6" lift springs also added afew from my old ones to compensate. The motor has 3 mounts the two side ones and a front one. Also boxed frame and made a custom square tube crossmember. Dang thing actually fits pretty good. Thanks for the help will have to do a bit more research!!

Yeah I will work on getting some pics!! new to the site need to get figured out also!!

get a different governor and a cable modulator from transmission center .com with the cable!!! mine rips

I actually posted a few post up , I am in the process of building a 2500 suburban 4x4 that has the turbo 400 , I have a line on a bus that has a 6bt but also has a allison and I was considering doing a devorced mounted transfer ... I think weight would be too much .
Not sure if you 4x4 or not ... just use a 1st gen dodge trans , I'm considering that my self and using a 205 , it has the front drive shaft on the side I need it .

Pretty sure the frito lay trucks already had the governor in the trans done.

Kickdown would just be a switched 12V applied to the trans.