1st: Make sure you mic the cam journals before you order cam bearings - have seen guys with .010 cam journals (and they didn't know it) - with STD bearings in the block. Cam goes in really easy . . . then wallows around . . . as you see low oil pressure and wonder why.
2nd: Before you even put the bearings in the block, check to see if they are the correct size and slide onto the cam journals . . . should be a nice slide-on fit.
Sometimes one has to hand polish the bearings once they are installed - as somebody managed to 'nick' them upon assembly . . . have seen this many times. I realize this should not have happened . . . but it does. A little ScotchBrite and some solvent . . . cleans things right up.
Third: If you're going to be running a mechanical fuel pump, make sure the rear cam bearing is correctly installed and that you can drop the fuel pump pushrod in and it goes through the cam bearing. Have seen folks put the cam bearing in wrong - never checking the fuel pump push rod . . . owner gets it home, puts his nice shiny new performance intake on it, tries to put in the fuel pump push rod . . . and it won't drop down. Whups! Time to tear the whole engine back down . . . yikes!