I don't believe they went with the MR spacing, they should be the same. A 2.19 has plenty of room, but I know on a C4AE-G, a 2.19 valve causes a very noisy and turbulent port. I measured .220 space to a std 4.05 bore on the intake side, but the exhaust is tight, .060. You might consider a small bore relief over there. Anyway, my guy has the turbulence and noise on my C4AE's with 2.19's and will be working on them soon. Just a heads up, you may want to have flowed to make sure they are not turbulent or noisy on your bore size. I would imagine BarryR's 2.2's StageX heads have the right work done.