Dear Jayson;
This is one of those times where there is more that one "right answer".
Using bronze guides is a 'high end' procedure and far better than what GM used in 1963.
However; An engine for a passenger car use will not need all of this effort & expense to function well and for this application a new OER valve, guide or O-Ring will work just fine.
You see the umbrella seal (Ford or GM) covers the guide completely, shielding it from the 'splashing oil', which is good for old/worn guides and saves the expense of knurling or replacing them for the customer.
For a 'precision engine' this is NOT acceptable as Ken states and the generaly used "just fix it" procedures are obsolete there.
Ken's customers demand this, because their (L-6) engines produce 700-1,000 Hp. which is several times what GM had in mind for the 250.
JM.....
