Which Inconel Valves are better the Manly Extreme Duty or the Fererra Super Alloy?

My motor builder refuses to use Ferra because they said they're spin welded to the shaft and they drop Valves BUT the Ferrera Super Alloy is rated to like 2,200*F quench on the valve face and with my 525SC tendency to get reversion that's appealing. I need 11/32 stems on a 1.88" & a 2.20" for my EQ320 heads.

So what's better Manly Extreme Duty or the Fererra Super Alloy and why?

Both great quality valves. I believe the majority of the people on this forum use Ferrea. If your having issues dropping the heads off valves you have other problems. Manley flowed better in my Merlin heads and Ferrea flowed better in my Dart heads. I've used both. I believe I put Engine Pro inconel in my Merc 420 builds. I asked my head guy for the least expensive that he trusts. I believe those were Rev.

Fierra will give a 40% military discount, includes vets.

Manley has been around longer and cost more. I would have no concerns using either one, but if you want your builder to stand behind it, I'd just use Manley's.

https://revvalves.com/valves/america...let/big-block/

manleys inconel are also spun welded. I liked Manley little more on the chrome stems.

I ran a high performance shop for many years. Ferrea was the worst to deal with. Had an intake valve fail and they insisted I send all intakes and exhaust valves. When I called to find out what they determined the cause of the failed intake valve to be I was told that all the valves had been put through destructive testing and they had no definitive answers. They would not replace any of the 16 valves. Since then I refuse to use them. I've NEVER had a Manley valve fail in any application over a 20yr span that I was a warehouse distributor for them.