360 into 64

Here is the detail on "grinding the head". It is NOT a big deal at all.

On the 360, there are elongated bosses for the smog port hole under each exhaust port. The number 7 cylinder is where the interference is. the drivers 273 stock manifold curves back to the port to wrap down and under the steering shaft. The 273 does not have the elongated boss. When the 273 manfold is placed on the 360 head, the manifold touches the edge of the boss, to the firewall side of the smog port. Using an angle grinder, take off a small area of the boss by the smog port.

The best way to do it is out of the car. put the manifold against the 360 head, you see right away where it hits. Mark it, grind away at the boss until if fits flush. Thats all there is to it.

You will also have to plug the smog ports. I drilled mine then tapped it (~ 1/4 deep) for a 5/16 bolt. I then coated it with locktite "green" and cranked it in tight. Then I used a cut off wheel and cut the bolt flush, its never coming out for sure!

good luck.