So my "built" 4l60E **** the bed after a year or so of use so it's time to upgrade. I have a 88 GMC 1500 which has a 5.3 mated to a 4l60E which within the year will be turboed and I am shooting for around 750hp. To prevent any future issues im going from a 4l60E to a built TH400 with a Circle D pro-series convertor. The trans is being built and the order is in with circle d. The truck is not a DD and will only be used for racing and running around town.

Being I have never ran a TH400 I know I need to hook up a electronic kickdown but thats about all I know. For the kickdown I was thinking about running down to the junk yard and picking up a kickdown switch from an older chevy to mount on the gas pedal. I there a better setup?

For the trans cooler I believe the 4l60e lines will thread right into the Th400 is that correct?

For the dipstick will the 4L60e work or will I need to order a new one?

Lastly for the ECU, being the trucks tuned for running a 4l60e will the truck run and drive without the trans hooked up? Or will I need to have the tuner delete the trans from the ECU?

Thanks for the helps

 

You will need a new dipstick, one from an older truck or car that had a 400 should work-ATI and others sell a dipstick that should work, avoid junk chrome ones that use an o ring
I have never run a kick down switch, just use the vac mod. and hook up vac.
If its limited use, I would go man shift, eliminate vac.
The lines might need a little bending-are they push lock type, or threaded
The 400 case might have the same threads as the 60E for adapters, although some 400's used pipe threads, not straight
I don't know about the ECU, my guess if would need to be tuned changed

 

Good info. I'll head down to the salvage yard and find a OE dipstick out of a TH400 truck.

The trans cooler lines in place are threaded as the original trans was a 700r4. I have not received the trans from the builder so I'll know about the case on Friday. I guess the worse case would be to redo the lines or just do the remote trans cooler under the bed with a fan.

If I ran a ratchet shifter (b&m pro ratchet) and the valve body was auto would I just not hook up a knockdown wire or vac line? Any issues there?

Thanks again for all the help