Is there a standard Steering Neck total Length with Cups and Dust Shields?

by Tim Snelling
(Fredericktown, Ohio)

I have a Pro-One Neck Cup Kit with Internal Stop. It says it's Designed for necks that are 5-11/16" long (not including the cups).

My Neck is 5-5/8" long. I have installed the cups and bearing into the neck. I have a total length including cups and dust shields of 7-1/4". Is there a standard total neck length? Do I need to add a 1/16" spacer?

Or, are front end trees adjustable enough to accommodate this?

Thanks in advance, for any assistance on this issue.
Tim