Hi guys, new to the forum but not Pontiacs.....so here's my question. Doing a 3800SC swap into a 86 Fiero and will be using the 4T65E-HD trans, what shifter are people using and shifter cable, as of now the car is a standard transmission, pulled a spare shifter from a 01 GTP and the shifter cable assembly also or will I have to source a Fiero automatic shifter and the Fiero shifter cable.
Thanks in advance.

Fiero shifter and cable works just fine.

Fiero shifter and some others uses 2 cables...
shifter cable and starter interlock.
interlock work w/ the AT steering column and ignition switch.

Some data, See my Cave, Auto Shifter

Interlock is does so:
Key locked = Trans is in Park.
Trans not in Park then you cannot lock the key and steering wheel.

Very easy to leave the car w/ auto trans not in Park. Parked "In Gear" means nothing for AT and engine off.
So Need Fiero shifter, both cables, ignition switch and column for correct conversion.

Full conversion needed wiring changes... Highlights:
To safely allow TC lockup. Same ECM pin runs Shift Light, runs the TCC lock. Brake switch(es) are wired to use TCC lockup etc.
To interlock the starter circuit w/ AT neutral safety switch.
Cruise Control wiring is different too.

Car cabin and engine wiring are different for manual and AT for this reason.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

GP shifter - cable goes to front. Fiero - cable goes to REAR