Any RPK parts kit that includes the front trunion and rear block will be for a stamped receiver. The front trunion and rear block are not found in kits from milled receiver rifles.
What type of RPK parts kit are you looking for - RPK47 (7.62x39, usually of Romanian origin), RPK74 (5.45x39, usually of Bulgarian origin), or M72 (7.62x39,Yugo origin)?