5.3l flex fuel motor swap for a 5.3l gas

[Papawolflopez]

Hello gents, am I able to take a 5.3 flex fuel motor with the eighth digit in the VIN number is 0 which makes mine if I three iron black flex fuel motor am I able to put just a regular 5.3 L to replace the flex fuel but do I have to change out the PCM?

 

[Doubeleive]

Hello gents, am I able to take a 5.3 flex fuel motor with the eighth digit in the VIN number is 0 which makes mine if I three iron black flex fuel motor am I able to put just a regular 5.3 L to replace the flex fuel but do I have to change out the PCM?

different vin number (8th digit) needs the original ecm for the motor, or the existing ecm needs to be tuned for the different engine
backbear can do it @BlackBearPerf
a matching 8th digit motor would be a direct swap

 

[petethepug]

This Gen flex fuel motor has software that calculates the alcohol in the ECM based on data from the o2 sensors. They do not have a sensor for alcohol like the earlier Gen did.

Pretty much any 5.3L Gen 3, 07-14 full size SUV motor will work as long as it’s running your current, higher rated injectors rated to run e85. The 2015+ motors with direct injection will not work.

Personally I’d replace the 5.3 with an 10-13 L86 6.0L iron block / aluminum head motor without AFM from a 3/4 or 1T truck. An all aluminum LY6 6.0L with AFM from a 10-13 hybrid is also a sweet drop in motor.

You’ll only be messing with the tune if you get a non AFM motor to switch it off or add an all aluminum 6.0L LFA from a 09 hybrid that did not run e85. Not 100% sure if LFA would need a tune though.