My father's '66 has a 350 set up like you mentioned. It has an Edelbrock 4bbl, I think 650cfm, late model vortec heads, a Sealed Power CS274 flat tappet cam, some aluminum intake, don't know what, Edelbrock performer or something probably. Can find out more if you want. I think the rest is just stock stuff. Runs fantastic and pulls great all the way down to idle. He drives real easy most of the time, has an M-20 Muncie and shifts @ 1,600-2,000, runs great down there. Driving real easy like that @ 50MPH or so and slipping it in neutral going downhill or stopping we figured he gets nearly 20MPG, runs real clean, too. Probably makes 300HP or so. I've driven it and like it a lot. Shouldn't cost anywhere near $2,000 to put together.
If you want to know more I can find out tomorrow.
-Chaz
Some of my crap:
1963 C-30 flatbed dually 292/SM420
1965 C-10 LWB fleet 250/column shift 3 speed
1965 C-30 9' stepside 250/SM420/4.10 gears (my DD)
Website I made for my crap:
http://www.66submarine.com