I would get the head. It will add HP. I dont think the reeds add Hp, mostly throttle responce. I would also go with 19 cc domes. I put them in all the pump gas motors I build. At my elevation 19's put me at 150-155 psi.
Another Banshee killer.
http://cgi.ebay.com/ebaymotors/1985-HONDA-...895403QQptZATVs
Should be called RIDER KILLER. Bacause it looks like a death trap.