[Squidward]

Since I have a number of less than desireable lo-po heads (i.e., small valve and press in studs) I thought I would convert over to screw in studs. I'm sharing these pix and information here to help any other intermediate level dude who wants to save some coin in upgrading their factory heads.

I tried the Comp Cams 5306 stud pulller/tap guide since it was advertised as Chevy and Pontiac compatible. It is NOT. So I returned that, and made my own puller/tap guide.

I started out with a 4" piece of 1.25" 304 stainless steel square bar. It cost me $10.64 from a local metal supply company. I then went to a local machine shop where I paid $20 to have a pair of 1/2" holes drilled 1.925" apart (stud to stud distance I measured), 1" from one end, and centered in the bar at .625". I requested only the dimensions above and that the holes be true perpendicular to the deck surface. So far, total of $30.64. I spent another couple of bucks at the Depot getting some washers and a bolt, so the grand total comes out to around $33.

1st pic is untouched #47 head. I probably should have started on my 7H1's, but I forgot and dove right in on the set of heads I plan on using soon.

After pulling off the guide plate and cleaning the stud boss surface of any crud, I put the jig over the first pair of studs and secured using an old rocker nut and a washer. See 2nd pic. I had to put the nut upside down to maximize thread engagement so it didn't strip. This happens easier than you might think.

I cranked on the nut, which takes less torque than you might think to start pulling. I then used varying combos of washers to continue pulling the stud. See 3rd pic for fully pulled stud.

After pulling the first stud, I then tapped the hole. Piece of advice: Don't go hog wild and pull all of your studs at once, because you need the adjacent stud to secure your jig for tapping. You'll have to pound a removed stud partially back in.

I used a washer and rocker nut to hold the jig in place. The jig hole is 1/2" in diameter while the stud base diameter is 7/16", so there will be a little slop that will need to be accounted for. Use a tapered starting tap, and put it in the other 1/2" hole. Wiggle it around a bit while turning it CCW so that you are able to center the tap in the hole and get the jig aligned before snugging up the rocker nut. Commence tapping. See pics 4 and 5.

I counted about 10 full turns before the tap hit bottom. Be careful, and don't go too far or you might risk breaking a tap or messing up your newly cut threads. The final few threads near the bottom should be cut with a bottom tap anyways.