Maybe the wrong spot for this, but am going to install a pyrometer to go with my new Predator, and have read about Hoot's method for tapping the manifold. Did a search, and did not find the original write-up. I understand the method, but I believe that the original article included drill sizes to use. Anyone have a quick link to the article? TIA.

http://www.dieselplace.com/forum/showthread.php?t=892

It was in the DIY section.:)

did it today, works like a charm. I used 5/16 as the final drill size before using the 1/8 NPT (1/8-27) tap.

Thanks Saguarokid, I looked there but obviously missed it. Will be getting to this soon. Thanks.

I pulled my off. it was easier

Did mine on the truck last weekend using Hoot's method, and the most time-consuming part was getting the splash guard off. It worked like a charm.