Matt is it sticking at the bottom of the cylinder or the top? Take glow plug out and take a look as you are pulling it and see where it is sticking.
Those washers help to prevent stripping out the wheels from over tightening. It spreads the pressure over a wider portion of the plastic. You should be able to run the truck to test it out but I wouldnt run it hard till you have the washers on.
The truck looks great. What are you doing for a body?
Which flywheel did you go with?