As mentioned before prime the pump, I like to use assembly lube or something heavy like STP, just pour some in the pump and rotate. Also the order to remove and replace, take the pan off first then the pump. Install the pump first (with driveshaft installed) then slip the pickup tube into the pump and bolt the pan up. Tighten the collar on the tube to the pump, pretty much take it down till it bottoms. If you pulled the dizzy for this project prime the engine by hand or with a 1/2" drill motor, if you left the dizzy in crank it with the coil disconnected till you get oil pressure.
God Bless.
Tim http://yblockguy.com/
350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor
tim@yblockguy.com Visalia, California Just west of the Sequoias