Originally Posted by cobalt327
I agree- the shop won't care- but I sure would!
Fluid dynamics and 'book learning' would lead one to believe there are many similarities in port flow dynamics regardless of the head design and application, and as far as that goes, it's true. But there are distinct advantages in choosing a company who's expertise is modifying the same head that you're working with.
The techniques/tricks of the trade and experience needed to do good work on any particular head doesn't come easily. Hundreds of hours can be tied up in a CNC program for just one port. A good shop might be expert in several makes/types of heads, but be sure of this before you contract to have your head done by any shop. It is a very specialized field, unless you're just talking about a routine valve job or rebuild.
I would recommend doing research to find out who is running good and winning using the head/engine you are working with. From there, find out who is doing the head work. Talk to guys who are racing in the class you're interested in, or who are building the engines for that class, etc. I'll be willing to bet that there'll be a few names you'll hear repeatedly.
You're talking about taking advantage of volume pricing. Which is why shome shops specialize in certain heads, they can distribute the r&d costs among more customers and get each a better deal. However if its a one off application that advantage goes away. My olds heads were checked by a shop that specializes in fords, that doesn't mean he would have been any worse than if I sent them to mondello. It does mean it may take him a little longer. Since I ported them already on my own he just touched them up and the extra cost of shipping would have been greater.