Assuming 53 gmc with 228.

Pull battery cables off
remove number 1 spark plug (front of engine)
Place your finger over the number 1 spark plug hole, and crank the engine by hand. When your finger is blown off the hole, you will be close to top dead center for cylinder 1.
Continue cranking the engine by hand untill the bb is visible on the bellhousing timing pointer. This should get you close enough to start the engine.
remove distributor cap and examine where the rotor is pointing.
This will be the location of your number 1 spark plug wire. Move the distributor body to line the rotor up with a spark plug lead that makes sence (I try to line number 1 up with one of the hold down clips)

wire plugs in firing sequence...1*5*3*6*2*4 clockwise
replace the battery cable
squirt some fresh gas directly down the carb
turn ignition on and crank engine

Did your engine start?