Paint the tip of the valve with a magic marker, then cycle the engine through the full valve travel with zero lash (if a hyd lifter) then remove the rocker arm and see where the marker ink has been removed from the tip of the valve. The wear area should be centered on the tip. All the valve tips should be the same elevation, check this by laying a straight edge across them all with the rockers removed. If they're not, then you may need custom length pushrods to compensate for the shorter valves. Be better to take the heads back to the machine shop and tell em to fix their messy work.

 

 

See 6565 in pic from 1964/72 catalog.

 

Then you'll need to crank the engine up before checking each rocker/valve tip to get the lifter pumped up. I know all about those shafts and how they're tightened down. Had several 390's and a 427

 

 

You have to remove the springs and put light checking springs on so you do not push the lifters plunger down while turning the motor over.

 

The few times I did it, I never did.

 

The easiest way to deal with the rocker shaft is to disable it by removing all the push rods. If the head is already on and torqued, Put #1 on tdc, put light checking spring on the valve, smear marking compound on valve tip, put adjustable push rod in and the rocker shaft. Set it at zero lash. Turn the crank through a cycle all the while watching that the lifters plunger doesn't compress. Take the shaft off and look at the pattern on the valve tip. Adjust the push rod accordingly and try again till you get a even pattern sweep across the tip. It should start in a little high of center and finish a little low of center. Once you get it adjusted right, remove pushrod and measure it with a 12" dial caliper, then add your lifters preload figure ( I always use .030) to the length you got and your done.

 

You have to replace them with checking springs. Otherwise the valve spring will collapse the lifters plunger leaving you with messed up false readings. It is very important that the lifters plunger does not move when you turn the crank.

 

Just an update... Per Steve Christ's book, acceptable space between the valve tip and rocker arm WITH THE LIFTER FULLY DEPRESSED/BLED AND THE PUSH ROD THAT YOU'RE CHECKING ON BASE CIRCLE: .100-.200. This is with non adjustable rocker arms and hydraulic lifters. A different method is used with solid lifters and/or adjustable rockers.

 

Are you trying to ascertain proper valve lash or verifying correct valve-train geometry?

The differing push-rod lengths form FORD are for adjusting valve lash on a hydraulic engine.