Lou the rear cross tube works great and IMO better than the grooved block or front cam journal
since it is a positive connection to the supply oil galley and does not rely on groove alignment or
oil hole alignment to accomplish oil flow.
You can have a solid 3/16" - 5/16" feed hole size restriction depending on what tube size
is used to feed the drivers side lifter bank which is much bigger than the front block
groove or cam groove restriction size is.
And after seeing the difference in front cam bearing wear I will never use a grooved front journal
cam again.