Mark the location of the rotor or set the distributor on #1 before you remove it. If you don't rotate the engine before the distributor is reinstalled you won't change anything. It can be reinstalled in the same location by indexing the oil pump shaft to match the slot on the distributor. Hook up an oil pressure gauge so you can make sure the engine has adequate oil pressure.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine