I would suggest calling anyone of the engine companies. ie. Mattituck, American Engines,. I used Eagle Engines in Redding, Ca for my engine. They are very helpful and i am sure they will sell you...
I was able to find my parts at Aircraft Specialties certified engine repair station at 918-836-6872. They can overhaul you parts or sell you refurbished or new parts. Also they A.E.R.O parts house at 800-831-5454. Check both out on line. Hope this helps,