I know exactly which header you need, but can only find them listed for .15's. Even if the holes line up, you may have to do a little Dremel work. Do you have a decent hobby shop nearby? May have to see what they have available. Make something fit. I've had to do that several times.
You're going to like that engine. Break it in right and it will be some fun. Have the same one stuffed into an HPI MT Racer.