Gosh, a lot of gents are suggesting a combo thats well over 1K. Lets face it, even the "cheap" Vortec heads are going to be a grand with the special gaskets, intake, rockers etc. , it will take to run them. My suggestion is to get a bone stock "roller camed" 350 and with a little luck, it won't need new pistons. When I go to the junk yard looking for a motor, I pull a head and "caliper" the bore, looking for ware (I found a very nice 400 this way...for 50 bucks!). Heck, even if the motor needs pistons, they can be bought for a song, on Ebay. Then give the stock heads a bit of a cleanup with a cheap Sears electric die grinder and then take them to the machine shop for the 150 dollar "special" valve job. Next, get a used "LT" roller cam from Ebay (30 bucks) and install a set of cheap SSI rings and Detroit gaskets. Slap on a set of used headers (I got a nice but dirty set for 15 bucks once) and a home rebuilt Q-jet and stock aluminum manifold and enjoy this combo for miles and miles. And best of all, if it's geared with at least a 3.23 rear..it will keep up with traffic and then some..guaranteed!