Need help with cylinder 2 and 6 misfire

[pb250r]

Hey guys. First off my truck is a 2000 ranger 3.0 flex fuel. I recently got 2 codes. Cylinder 2 and cylinder 6 misfire. So far I replaced the plugs, wires, and coil pack. I also put a new fuel filter in and ran a sea foamed a tank of fuel. I only get these codes at highway speeds over 65mph. The truck runs completely fine with no sputtering. I find it hard to believe both injectors are bad. I also wouldn't think it's a head gasket because they are different sides of the engine. I'm lost. Any help would be appreciated. Thanks in advance!

 

[funkingonutz]

what kind of spark plugs did you use??