[SS Engine Guy]

Trusting the supplier to do the right thing is the wrong thing to do. The builder should always verify what can and can't be done with tech. Usually in the form of a letter. (however, in the past few years, even a letter isn't worth the paper its written on). There lies the problem. Tech has been over ruled so many times that its all BS. I have freshened many "legal" pieces that had the proper # as per tech and were built totally different than the spec or intention of the rule. Its not hard to stamp letters/numbers/logos on parts.
Like Alan, I have had parts held for long periods of time, finally approved and then notified weeks and even months later that the approval was void. I have made it right by re-doing parts, no charge, even to the point of buying the newly re-defined part at my own expence along with machine work and other parts that were necessary to make this piece "legal" and make it work correctly. Then watch what I was NOT allowed to do go right thru teardown without a word said.
As much engineering and design as was supposed to be done on these super car engines (Ford,Mopar and probably Chev.) there is no excuse for any of these people to be dq'ed. Except for the fact that there is apparantly a lack of knowledge as to the amount of blueprint time required to build a truely fast and completely legal S/SS combination under the rules and guidelines set forth by the santioning bodies. Also, a lack of communication between manufacturers and tech. The attitude of building a regular car seems to be: put it out there and we will work on the problems as they arise. Any dealer tech can tell you stories about the amount of tech bullitins, recalls, replace it free only if the customer complains enough, etc...

Sorry for the long post but I know what its like trying to get a straight answer from aftermarket suppliers and from tech depts. Also, I didn't know there were different ways of measuring the diameter of a valve.