I tacked my divider in with Muggyweld rod, it won't crack and will never come loose. I sure as heck didn't heat the entire head up other than about a one inch area around the tack welds. Jeez, it isn't 1950 anymore. 400 bucks for a couple tack welds is asinine. It would be cheaper to buy a round trip ticket, fly up here with the head, rent a car, and see the sights while I tacked the divider in. So find a shop that has heard of muggyweld rod, or buy some and bring it with you. Welding technology has evolved somewhat since the bad old days of junk nickel rod on preheated cast iron (weld/pray/crack/warp/junk).
Ford USA, Oz, and Agentina, didn't redesign the siamesed exhaust port design to improve performance because it would have been expensive to do. Not only would the head casting pattern have to be re-built along with the corresponding core molds, but the exhaust manifold would need to be redesigned and the gasket updated. The log head was never a performance design to begin with. And Ford did address the I6 performance problems, at first with a 260, then a 289, and 302.
The 3-4 exhaust port was designed to heat the carb base for better fuel mixing, not for efficient flow.
When Ford Oz decided to make the six more of a performance engine (crossflow), like proper engineers, they dumped the whole original head and started fresh.
The Argie's made the best of what they had and came up with the 221 ME and SP. The log and 3-4 siamesed portion of the exhaust ports has been eliminated. The head mold looks like it was just run through a bandsaw, much like the de-logged heads that a few of us have experimented with. No real retooling needed to cast a 221 head. Same thing with the Oz 2V head, just a hunk of the original head pattern was chopped off. It's cheap to remove sections off of an existing pattern, and very expensive to add.
If you don't use a divider when using headers, the exhaust gasses slam into an inch tall wall on the way out of the head. Not the best thing for breathing. You will see a LOT more than a 1% gain with a divider and headers. The stock cast manifold is crap, nobody interested in a performance increase is going to use it. I don't see much use in the divider if you are using a stock exhaust manifold in any case.
Rick(wrench)
william
