76- 4oo engine Can i get 500-550HP stock exhaust

MRL Performance said
Just a set of RPM heads cleaned up a bit, headers and a cam with around 235-240 duration will do the job. You dont need EZ heads to make 500hp. Good ported stock heads will get 500hp and they dont have to be hogged out to get it.

SBM stoker 408's make 500hp with RPM heads pretty easy, BBM should be cake. Its just a lot harder to do with manifolds.

But? Can they do it and still maintain stealth quality? No nasty lope and with quiet hydraulic lifters. I recognize you are the expert but a little overkill compensates for other build short comings we amatuers tend to have.