68 Bed question

[WhiteZ_02]

Hey guys I am new to the 67-72 world and I have bought a 68 swb project that was partially completed. The cab and fenders were already painted. I have got the bed together and painted now but it isn't lining up very good with the mounting holes or the body lines on the cab.

My questions are

Do you guys usually have to shim the bed and cabs for the body lines to be right?

And my newbie question is which way do the bolts on the head board of the bed go? I have mine going through from the inside and it looks like they are going to hit the back of the cab when I slide the bed up far enough to line up.

Thanks in advance for any help you can offer