Re: problems with guide plates and roller rocker to valve stem alignment
not sure what brand of guide plates you have but there can be a simple reason for this.
Many guide plates are made to suit 5/16 pushrods and often people upgrade their pushrods to 3/8 causing them to rub against the guides.
Two choices, grind your guideplates, or cut and reweld as mentioned above.
Alternatively, get a set of hardened 5/16 pushrods then you'll have no worries at all.