how to tell if Silverado is E85

Bleepster · October 7

father-in-law has a 2011 Silverado, 5.3L. previous owner swapped motors. how can we tell if the new motor is E85 compliant? we cannot get a hold of the previous owner. thanks

newdude · October 7

1 hour ago, Bleepster said:

father-in-law has a 2011 Silverado, 5.3L. previous owner swapped motors. how can we tell if the new motor is E85 compliant? we cannot get a hold of the previous owner. thanks

2007-2013 the flex fuel 5.3s were the RPO code LMG iron block and the LC9 aluminum block, so if the engine is an LMG or LC9, its flex fuel. Salvage yards typically are good about asking for the 8th digit of the VIN to find a matching engine as the 8th digit is the engine digit in the VIN.

As far as identifying the engine for sure, there should be an engine ID stamped on the left rear block pad just behind the cylinder head. The last 6 digits of the vehicle's VIN that engine came from are the last 6 of that ID number.

Edited October 7 by newdude

Bleepster · October 7

thanks for the information. its Monday, and I am a bit foggy - so, I will instruct him to look for the digits stamped on the block. once he has those digits, what are we looking for?

IE - the LAST 6 digits on MY vin are 382696 and the eight digit of my VIN is 3

Edited October 7 by Bleepster

newdude · October 7

1 hour ago, Bleepster said:

thanks for the information. its Monday, and I am a bit foggy - so, I will instruct him to look for the digits stamped on the block. once he has those digits, what are we looking for?

IE - the LAST 6 digits on MY vin are 382696 and the eight digit of my VIN is 3

So with the last 6 if it can be found on the block, I have a contact who can check the build sheet of that to see what engine it should be.

You have the 5.3 aluminum LC9 flex fuel for example based on your 8th VIN digit.

Edited October 7 by newdude

CamGTP · October 8

Any 5.3 can run E85, the block and pistons don't care. The only thing that matters is the injectors if it's a complete engine from intake to oil pan. If you used the intake and injectors and stuck them on the long block, you are good to go.