I dont know about how economical it is to shell out $$$$ for the conversion, but to me it would be worth it just to prove the point that you can make a high performance muscle car using "green" technology. Besides, if I front 15K to do a complete EFI ethanol conversion on a Challenger now, and it runs a 12.5:1 360 with aluminum heads, I guarantee you that in 10-15 years I will still be driving that car regularly, and it will blow the fiberglass off of any Prius you send my way. Of course, it won't be historically correct, but that's not why I got into this hobby.