Valve nitriding services?

Bless these Boards, as there are few places I can ask this! Where can I have a handful of custom (Chief) valves nitrided? I can have them hard-chromed, but I am not in love with the result. The main problem is that they are stainless, and the guides are soft cast iron, and I expect 1200+ F exhaust temps, (but you knew that...)..Thanks in advance!..Cotten

Rowe mfg might do it for you

Cotten: not that this answers your ??, but what's your experience with bronze guides?

There's a time an a place for everything, but rarely would I suggest bronze or Ampco 45 for a flatty. These materials have a habit of swelling under extreme heat. I have known of Aluminum headed OHV's that ran excellent in Illinois, but stuck valves bad in Arizona heat. It's always Arizona inside a Chief.
I haven't tried Rowe directly yet, but most smaller suppliers had a $150 minimum! Still searching....