Find a 2bbl intake. You can find a MP 6 cylinder book and get the porting templates. Most of your gains will be in the bowl area behind the valves.
Engine builder oversize valves are $72 on Ebay. Go to
www.slantsix.com and check out the Erson group cam buy. They sell a cam designed by Doug Dutra for the street. Plus any other cam you might want. Might scan the Craigslist in your area for free or cheap slants. That way you can get one to build while you drive the one you have.
BTW Ray is from OZ so you might need to translate it into North Carolinian
