I own a 2009 F150 with the 6R80 Trans. I知 looking to swap the 5.4 for a 5.3 Vortec and I知 wondering if I need to buy a new trans or if I can put the 6r80 on the 5.3. Looking for answers ASAP

 

Haven't seen that combo used yet. I think you're gonna have some trickery to work around, starting with the bell housing pattern and ending with keeping the trans controller happy with life. That might be simple if you can add some Ford sensors to the motor and get all the inputs the trans wants to see like TPS/ RPM

But the bell housing pattern still isn't the same. And that's the first hurdle

 

The LS computer can't control the ford transmission. So if you ask me that will need to be a full standalone transmission controller.

I wouldn't even try to run a stock computer at that point either. I'd be looking at a Holley stand alone to control the LS engine and figure out transmission control from there. Needless to say that nothing in your ford chassis will ever really work again. Like cluster, ABS, traction control etc etc.