i dunno if a 4bbl would be a good idea unless you put a wild cam in there.... but as i've been told... camming an inline 6 isn't a good idea... cause they tend to never idle right once you put a cam in it... probably best to leave it a 2bbl, roller rockers, maybe bore it out a lil, get some headers, they do make them... if you really want to get tricky, you could have your head milled and raise the compression just a little bit...