Need help, '68 F-100 360ci.

On Wed, 23 Feb 2005 02:56:54 -0800, Jessie Herrera rearranged some electrons to form:

Or even better, the Pythagorean Theorum.

I have exactly the same set up on my '73 F250 XLT with the 390 engine. However, the bolt hole on my exhaust manifold is virtually perpendicular to the flat surface of the horizontal boss. Do you still have the old manifold? If so that should give you a real good indication of where the hole should go. If not simply bolt the bracket to the back of the A/C compressor and see just where the hole lines up on the exhaust manifold. I'd simply punch a mark, drill down a half inch or so (no more) with a 1/8" to 3/16" bit as a starter hole. Remember, you're drilling cast so it will drill differently than standard mild steel. The drill tip needs to be dressed much flatter than that used for steel. It seems to me that the hole is tapped 1/2-13. This can be a problem if you don't have a "bottoming" tap. I have, over the years, gradually made "bottoming" taps by slowly grinding down a standard tap. If you do this be sure to take your time doing it since you can change the metal characteristics dramatically if you get the tap too hot. Secret: grind a little then cool quickly in oil. Grind some more, etc. Try not to let the metal get hotter than you can stand by holding it about a half inch from the area you are grinding on the tap. If it gets hot, stick it in the oil. Good luck.