Just wanted to add to this. There has been previous grumblings and complaints I read here about Indy Cylinder heads customer service in the past. I had nothing but a positive experience. I was on the phone with them most of the day with all my questions and they went above and beyond. One of the engine builders called me to answer some of my specific questions. They did not have these heads sitting on the shelf, they got them done and to Sean in 4 days. Nowadays so many companies customer service is terrible. I can only speak for my experience, but they were great to deal with and I would not hesitate to buy from them again.