If its a 1000 series fastram perkins timing marks should be on the gears, key way in crank shaft gear should be more or less striaght up.
New pump should already be set a top dead on number 1 (locked with bolt in side of pump)
you should be able to see where the old pump key way was on the old hub as they normally leave a very slight mark even though they are not keyed to hub.
If you have the 1100 series perkins i remove rocker cover set valves of number one on the rock then use a drill bit which goes through a hole in block to lock crank shaft. lock up fuel pump with lock bolt on side and pump is set a number 1 top dead. take it off do what you have to and refit.
All new or refurbed pumps should be set at number 1. if you have lost this setting you should idealy take it to diesel place to get it reset, if your lucky you can remove locking bolt look in hole and you might see a mark on the shaft where it was locked before.