Hey John,
Look in Fel Pro medium and heavy duty truck and tractor catalog. I just found mine, it has DS6202 Continental, the part# for early OS 1279 C, late OS 1279 AC. Those number should work, I had a top end set ordered thru Warehouse, but they don't sell to the public. They might be able to order from Advance Auto Parts, I've seen Fel Pro in their stores, or cross over to something else. I got little brothers head done, seems it will work.
Take care!!!
Andy