Deck height

Yes, I thought 3.440 but measuring twice I come up with 3.435. Maybe its user error but I do not see how at this point.

Measured again and there is a pretty heavy coat of grease at the top of the cylinders, I usually get 3.435 but sometimes see 3.437. Hard to get up there lean in also cause the truck sits kinda high.

The 'crud' at the top of the cylinder can cause you not to get an accurate reading. I would use a 3" wire wheel on a drill to knock off any carbon ring/build up and then measure with clean metal.