port/polish hp gains?

[slow_one_eight]

I have been considering doing a fairly radical port/polish job on my little one-eight. It is a fairly new j-spec block (it is a cyclone, or so the valve cover says) with about 50k miles. I have been told many different stories about how much hp i can gain, and I really want the plain facts instead of the mixed responses I have heard from many of my friends.

 

[qwall]

you won't get a definite answer because we don't know what kind of porting you're talking about. Is it runners porting, if so how much? are you gonna port inside the head too? All that and the fact that every porting is different, no one can tell you exact hp gain, but they'll be there, that's for sure.