Well you certainly can have a lil' engine that bites, but there goes reliability. You won't get 150k miles if you rev it to 6k rpm often. Why don't you consider a 1776 (90.5 x 69). It's relatively small, 1.8, and it sure can bite at 6.5k rpm with proper heads.
I'd say that if you must rev it better go with 1776. Same thickness as stock, unlike slip-ins.
Just what i think
... And my foot IS heavy
with my 100% stock 1584cc i get about 20 mpg at best