This is an example of what comes in the Hedman Hedders "box of mandrel bends" along with the slip-on collectors. Looks like headers to me!

Not bending the tube immediately after exiting the port was an important to making power.  

Another detail that is very important is the initial bend of the primaries out of the heads. You can have the big tubes but, if they take an immediate 90-degree turn out of the port, the exhaust hits it like a wall and that kind of defeats the purpose of custom headers.

So, I was armed and dangerous with knowledge and ambition, and ready to get started. The first thing I did was look up a couple different header manufacturers on the net to see what was available. Everyone makes “J” tubes, 90-degree bends and such, but I was mainly concerned with finding flange plates that fit Yates-style heads. I also wanted the plates to have factory installed and welded header “stubs” so that I could slip the new tubing over the stubs to help locate and secure the header tubes during fabrication. A “third hand” if you will.

After looking at a few options I went to www.hedman.com and Hedman Hedders ended my quest. Hedman Hedders has been in the business of producing a quality product for longer than I have been into cars. They have a large selection of street- and race-type headers for literally every popular engine and chassis combination known to man. They also offer weld up kits that fit certain engines with certain chassis that allow the builder to make custom headers out of a kinda sorta pre bent kit.

And for the hardcore do-it-yourself masochists like me, they offer the “box of mandrel bends.” BINGO! I went with part #12024, which is a 2-1/8” tube diameter. The kit comes with (10) 180-degree “J” bends, (4) 90-degree bends, and (4) 120-degree bends. All of the tubes are precisely bent on mandrel bending equipment, which gives a very nice kink-free radius to the bends.

For the flange plates I went with part #11430, which is listed as Ford SVO 351-(Yates Style) and they have 2-inch diameter stubs factory welded to the 3/8” thick flange plate. The 2-inch stubs are a perfect slip fit for the 2-1/8” tubes to slip over and I only used about a half inch of the stubs, so no real obstruction is present considering the exhaust ports in the heads are 1-3/4 inches.

What really sealed the deal for me is that the port openings in the flanges are a perfectly round hole that matches up beautifully with the round exhaust ports in the Yates D3 heads. The older style Yates C3 ports were more similar to a stock 351 Cleveland in that they were kind of a rounded rectangle shape. However, these flange plates will work great with C3’s also. The D3’s exhaust ports are raised slightly higher on the heads but the bolt pattern is the same. So, on my heads the very top of the round openings of the flange plates are just at the top of the ports in the heads. Perfect.

This is the pile of what I had left from the kit. Lots of cutting!

Also, I was very impressed with the finish port work the people at Hedman have done to the port openings in the flange plates. There is NO weld slag or jagged edges in the opening and the transition from the plates to the stubs is smooth and well blended and the flat surface of the flange is actually flat because it is belt sanded.