I just acquired a 348, this site is a good resource:
http://www.348-409.com/ I would look for a 1961-1965 block, but the earlier blocks are good too. I found a lot of rebuild/speed equipment for a 348 (check eBay, plenty of vendors out there that specialize in 348/409 engines). But, you do have to look for them. I would agree, the 283 parts appear to be cheaper. While the 348 is a big block it is not too much bigger than a 283. A lot of Chevy V8 parts (e.g., motor mounts)are interchangeable. I like the look and uniqueness of the "W" engines.
