Bill C wrote:
I think we need to look at this topic from a cost to the racer vs. a performance gain.
For example, several tests have been done on Chrysler Big Block Heads showing that there is little difference between the 906 & later production heads and the 906 heads cost more than later heads. If the later heads do not offer significant HP gains and look correct, why mandate that a racer with a '68 - '70 MOPAR must have the 906 head to be certified.
Your right Bill
![Thumbs up :aok](./images/smilies/thumbs.gif)
. Using a 906 Chrysler head is an example I am familiar with and a head that is very available for little to no cost for virgin castings. Example; If a racers was building a 1967 GTX 440 and did not have a set of correct 915 heads, and our rules allowed the racer to use a 906 or later head that had no performance gain in virgin form, that would put him on track quicker. Agreed?
Another example, one of our racers is building a Max Wedge. He had to purchased 3 sets of correct Max Wedge heads till he found a set he was able to work with. If SuperCars allowed him to run a 906 on the Max Wedge, that would of help him complete his new build quicker and also the cost of virgin Max Heads are way more than a 906 or later head.
Another example, one of our racers has a 1966 Chevelle 396. 1966 396 heads are a one year only casting number (like 1967 440 heads 915), he has had issues finding a set that will last. If we had a standard factory replacement head we could offer him to use, he would be on track as well.
Another example, 340 X heads and J heads in virgin form have no real performance advantage. Once you port either head they perform the same. Why not allow either head to be used on a 1971 Duster 340?
Bill C wrote:
The one potential problem is where due you draw the line? Do you allow '69 big block Chrysler intake manifolds to be run on a '68 MOPAR since the casting is essentially the same except for the part number?
Intakes are not an issue, Cylinder heads are.
My point is, we are all in the same boat here. All three marques (GM , Ford & Chrysler) are having issues finding good virgin casting that can be used.