EDELBROCK PRO FLO 4

The tap guide grew legs, so I improvised. I was only using the head to keep the tap aligned with the hole, I drove the tap by hand.

Helps if you have a lathe or a buddy with one. I have probably a dozen 60 degree center pilots of various diameters and lengths turned from drill rod. The different diameters help keep from having to change the collet diameter and different lengths help keep from having to crank the table up or down if you run out of spindle travel. I've been meaning to build one of the spring loaded ones but other things keep taking priority.