I've been looking into getting a new cylinder head and was wondering if just porting the stock head would yeild good horsepower gains?

 

Porting and polishing your stock head will make it like new. Because of downtime situations and people needing their cars as daily drivers folks will buy a ported and polished head from Thumper,RMW etc. so they can just swap out the head in a weekend project thing. The only drawback is you are going to spend over 1k for a professionally done head, unless you have the tools and skills to do the job yourself.

 

Why are you looking to replace your head? Unless you've done all the usual modifications (pulley, intake, exhaust) porting the head is one of the last things you'd do.

 

Head porting is something that is left to the professionals. Its a place that you don't skim by and do it as cheap as possible. IMO only get one if you have at the header to support it as it will just choking for more flow.

Get a CNC machined head from a reputable company; RMW is considered the gold standard of Mini heads. there are many different options, most cheaper, but alas. Not as good. Thumper, eydne, etc.