help with crate engine/question

[nac593]

I bought a 350/290 hp longblock crate motor. There's a piece of cardboard where the intake manifold goes. Under the cardboard is a bag with 2 timing cover marks that you bolt on and 2 pins. Where do the pins go? Maybe one plugs the extra dipstick hole? They are different sizes. 5/16" and 3/8"
I called chevy and they don't know. Please help