I decided to start a new post to help answer the questions floating around about the GT40 heads and to showcase my new engine a bit. I almost went with the GT40 heads myself on my 69 351w, but after looking into all the machine work and costs, it wasn't really worth it. The old GT40 heads after all the work still don't flow all that great. So I started the hunt for some new heads. Edelbrock, World Products, Ford Racing? After talking a few things over and doing some research, I found that World Products made the best heads for the money and performance for my engine rebuild. You can get these heads complete or bare from Summit or Jeg's. These have worked excellent. I went with a Ford Racing cam, Weiand Stealth manifold, Holley 700 DP, Keith Black pistons, Heddman ceramic coated headers. Just to name a few parts. Similar build-ups have produced about 420 HP, so mine should be around that range. I looked into the GT40"P" heads, but was told they are over rated and you have to do some mods to get them to fit. Wasn't really worth it to go that rout. The World Roush 200CFM heads flow like nothing else. They bolted right up, no mods were needed. Couldn't have asked for an easier bolt-on. The spring range is pretty wide, so you can pretty much pick any grind of cam without getting new spings or they can match the head with larger springs. Below is a link to some photos (a new K&N air cleaner has been added since the photo)and to the World Products web site. Hope some of this helps.
http://mercurycougar.net/forums/showthread.php?s=&threadid=2757:1poke:
http://www.worldcastings.com/downloadcatalog.shtml#ford
http://mercurycougar.net/forums/showthread.php?s=&threadid=2757:1poke:
http://www.worldcastings.com/downloadcatalog.shtml#ford