Within Stock rules???

[Dwight Southerland]

Jim - Both of those rules are in reference to replacement parts. The first rule about the valves was inserted at a time when the allowance for parts was not as liberal as it is now. Some versions of 427 Fords came from the factory with hollow stem sodium filled exhaust valves. The factory was the only source for the valves and discontinued production. Some racers petitioned to allow titanium valves as replacements since the hollow stem valves were lighter than available solid stem valves. There was some controversy that started because the West coast tech guys thought it was all right, but every body else did not. When it was pointed out that the titanium valves deviated considerably from the shape of the original valve and provided a two-fold advantage, i.e. lighter weight than even the hollow steel valves and increased airflow, the prohibition on titanium replacement valves was the solution. The second rule was included in the change to the rule to allow replacement spring retainers. When the rule was first drafted, it merely stated that replacement retainers were allowed. Of course the ingenious racers interpreted that to mean that ANY retainer was okay, including replacement titanium retainers. The additional statement prohibiting titanium was added to solve that. In both cases, the rule pertains to replacement parts, not OEM equipped. The factories can do whatever they want as long as NHRA accepts it, which is what we are seeing in the shootout cars.