Well, you want a 427 FE that is also
"a nice street engine running on pump gas and ... will never see the track." Any of the regular builders around here can put together that engine and it will have well over 500 horsepower. They will dyno it, check for leaks, listen for any unusual sounds or vibrations, and then pronounce it complete and ship it off to you. They will be fixated on the HP/TQ numbers and, to them, the higher the better. Getting that engine to have some manners, after you've come off a hard highway run, and you're now sitting at stoplights and crawling through traffic, with under hood temperatures of 200+ degrees, will be tricky. It can be done, but it will take both foresight in the build and tuning finesse, and both of those tasks will fall on you.