[Jason]

I might get a 1992 3500 chevy truck. It originally had a 4L80 but it's gone, the driveshaft and cross member are there.
It has a 454.
Would the th400 bolt in? I know it'll bolt to the engine and all but my concerns are bolting it in the chassis. I have never even seen a 4L80.
Does the 4L80 use the big yoke like the short tail th400 or the small yolk like the later model long tail th400.

[Crosley]

it will bolt into the chassis.

move the crossmember where needed.

4L80E uses the large diameter yoke

Due to the year of the truck I am not sure if the PCM will look for feedback from the tranny and set a DTC if none is found. I would think it will set a DTC

[Jason]

It may be a '91, I'm not sure.
Is there anything that can be done to prevent getting a dtc?
Would it affect performance or just put out a dtc?
What does the trans send to the computer in this application?

Thanks.Heres a link to another post about the truck itself.

[Crosley]

The PCM should be looking for a signal from the force motor(PCS) that controls main line pressure in the tranny.

A resister that is 5 ohms @ 5 watts will stop that problem. Plug in or splice in the resister to the two wires that feed the force motor.

This is something that is done when a 4L60E is converted to full manual shifts and vacuum controlled main line pressure.

[Jason]

Thanks