There is a right way and a wrong way to torque down screw-in rocker studs on top of guide plates.
The wrong way is to torque the studs with the cylinder heads OFF the engine. This can lead to all sorts of problems including broken rocker arms and binding pushrods.
The right way is to torque down the cylinder heads first and then attend to the rocker studs and guide plates.
With the rocker arms roughly in position and the screw-in studs fractionally loose on top of the guide plates, spin and wiggle the pushrods, making sure that the ends are seated properly. When the first guide plate is correctly positioned, clear of both the pushrods, hold the guide plate firmly in position with a thumb whilst torquing down the two rocker studs.
It is possible in some cases that the guide plates will need modification in order to obtain adequate clearance.
Repeat for the other 7 guide plates.
If you are replacing the stock press-in studs with the screw-in type, do remember that the stud bosses need to be milled by 1/4 inch first. Then the stud holes need to be tapped absolutely dead straight using a 7/16-14 tap.
Screw-in studs invariably go through into the water jacket, so it is essential that the threads are first coated with a locking sealer such as Loctite Lock 'N' Seal.
The stud torque settings are:
Cast iron: 60 to 70 lbs ft.
Aluminium: my Edelbrock Performer RPMs are 45 lbs ft but do check with the individual manufacturer first. This figure may be incorrect for your make of aluminium cylinder head!