Whew! All good info but their engine prices are almost as high my total build budget! Good info for research though. I have found a local builder with a lot of verified FE experience and we are already in discussion. My goal is 500/500 which he said isn't a problem these days and as stated above it will be reliable enough to road trip occasionally when desired.
Four things that are relatively important if you go local (which of course can be just as good as any of us anywhere else)
1 - Have the block square decked off the mains. Not too many guys cut the deck without aligning to the mains anymore, but there are still some. I cut minimally to the deck height I need for the most crooked side. Lately, 10.155 has been my lucky number. You then can buy pistons to match your head gasket / deck height combo to get the desired quench. It's amazing how crooked old engines will be front to back and sise to side.
2 - Sonic check and bore minimally, the thicker the wall you can end up with, the better for ring seal. FEs are all over the place, and there is no standard for cylinder wall thickness. It's not a problem usually, but you need to be aware before you build a flexible cylinder wall
3 - Have the block honed with a torque plate. Often shops don't have one for an FE. It makes a huge difference. I had one 445 here that distorted .008 after bolting a head on, and that was a fresh bore, fresh deck, but not done with a torque plate. Huge amount when clearances are .0035 or so. It was a thin block and we ended up converting that one back to a mild 390 and found another block, but regardless, even the best blocks crawl a little with a head bolted to them
4 - Just technique, but I replace all push in galley plugs with NPT plugs. Never had a push in failure, some have, but it makes it really easy to wash and just thread them all in. The cost is minimal when doing block work
For a reference, I don't do my own block work, and I bring quite a few through my guy, but after I strip all the parts and bring a bare block. Clean, cut, bore and deck plate hone, with NPT plugs (you can do them yourself, but it's nice to have them run it through the tank to clean a bit more) I am at about 800 dollars. The difference is worth it though. Deck heights, bores, etc are all spot on
One last comment, 500/500 is not hard to hit, but is not falling off a log either. I would consider a set of Trick Flow TFS heads and build around them with an Edelbrock RPM manifold. Their runner volume is relatively small, although they have a few quirks like small chambers and you need to cut the rocker stands, it will allow you to make the power with a bit less cam. His comment of "occasional road trip" is odd, there is no reason if done right you couldn't daily drive it. Especially if willing to spend the money on a hyd roller cam. 1.16 hp per cid is absolutely attainable, but keep in mind that if you stay 433, then you will need to rev it a little more. I'd much prefer to see 445, 461 or bigger to make the power at a lower RPM in a Gal.