Very ambitious...and most likely not possible. People have enough trouble getting the four cylinder 8valve 2 litre Alfa TS engine into Spiders..never mind a V8. (Its taller than the standard Alfa Engine)
The concensus on the Alfa Digest
www.digest.net is that turbo charging is the best way of getting max power out of a Spider, but only if you know what you are doing. However, most people are content to enjoy the car as she as designed to be enjoyed, and in some cases..less is more.
Good Luck whatever you do with her!
Tim Hancock Boston UK
164TS
164Super