[Excaliber]

Adjustment methods vary to much for me to speculate on how yours might work, assuming you even have adjustable type stands. But end supports, at the very end of the shaft, are a common upgrade to prevent breakage. Turning 6,000 to 6,500? Yup, you GOT to have end stands. You should consider going with a whole new after market type rocker assembly, stands, shafts and rockers. The only problem with that is, they ARE expensive! An option would be careful reassembly of the stock components, ALWAYS making sure your valve clearance is correct and limiting rpm to 6,000 (IF that) or even lower.

Note: IF your valve clearance needs frequent adjustment and is out more than a few thousands at any given time, SOMETHING is wrong with the valve train components. When everything is right, valve clearance changes very very little even over many thousands of miles. Set it, check it on occasion and forget it, no adjustment (or very little) should be required.

The stock rocker arms you are running sometimes have a bad fitting adjustment bolt that loosen's up prematurely, causing to much clearance and stressing components. Ford used to sell slightly LARGER/FATTER adjustment bolts for a tighter fit in the stock rocker.

I don't really know much about the oiling pressure/volume concerns of a side oiler vs a center oiler. Rick seems to have it covered well.