There are a couple ways to look at this and of course this will be another rule that is open to interpretation.

If you read the statement literally it says the exhaust port height has to be 4.50mm. The rule as we understand it is that it cannot me more than 4.50mm.

I am wondering if they are not removing this rule because the wording that was used is telling people that they have to run 4.50mm no matter what.

Dennis, you want to take a crack on this one? If this is the case, there are going to be allot of changes to the engines, and all the $300+ .12's that everyone bought were all built under the 4.5mm max height. This rule could really make things expensive.

Duane