Eight digit

[OR VietVet]

Welcome to the forum. In the future, to help avoid the confusion of post #2, you might want to post the rig info in your signature so it is there every time you post.

 

[91RS]

You have an L83 which I believe can be optioned for Flex Fuel but not all are equipped. If you have no badging and a black gas cap, it isn't Flex Fuel.

 

[Fless]

You have an L83 which I believe can be optioned for Flex Fuel but not all are equipped. If you have no badging and a black gas cap, it isn't Flex Fuel.

His has the FHO RPO code:

Note: Vehicles equipped with RPO FHO, E10 gasoline are certified for this fuel type and cannot be modified to allow use of E85 flex-fuel.