We built Jim's (66JamesStang here on the board) 408 about 3 maybe 4 years ago, we started with a 1970 351 block and bought a 408 stroker kit, Edelbrock Victor Jr. heads, RPM Air Gap intake, a BIG Comp Cams retrofit roller and a 700 cfm carb. It is a screamer, If I had it to do over again I would do with a LOT less cam.
IMO he is pushing about 450 HP right now and was probably was closer to 500 when he was running his Mighty Demon carb.
His Compression ratio is a touch over 10 to 1 with 60cc chambers in the head, the stroker kit is not a brand name one but we bought "H beam" rods it is super tough and by going with the H beams, you don't need to clearance the block for the stroker kit.
About 2 years ago I built another 408 for my avatar, this time I bought an assembled short block off of an eBay store, (the price was less than I could build my own so I took the chance and bought it). I went with the Edelbrock Vic Jr heads again (these heads do not get the respect they deserve!) and went with an Edelbrock ProFlo2 EFI setup. The c/r is a touch over 9 to 1 on this one and I am running a roller (this one is a roller block) Ford E303 cam. I built this engine to be a mild mannered "driver", but it ended up being a bad ass too. While I have not had the car on the road yet, around the lot it will spin my 14" wide M/T radials at will in 2nd gear.
A 408 makes a great engine, super torque, reasonably cheap to build, and a lot of fun. I am sure I missed some stuff but you can shoot me a message or an e mail anytime!