[327 / 350 hp]

Took off vavve cover today to find #7 int rocker at an angle . Stud broken and somebody bronzed the stud where it is in head...????? Seems like i can pin the stud on the car..May have to remove intake..Its a 70 350/ 370# heads. Anybody familiar with this. thanks.. jim

[BOBCRMAN@aol.com]

Best way is to remove the broken stud. Then tap the hole for a screw in "repair stud". These are the same diameter upper but have threads that screw into the head. Any good machine shop should have them in stock or get them from Pioneer products, Champ, etc.

[302 Z28]

Most screw in stud applications require that a flat be machined on the stud boss for the screw in stud to jamb up against. Short of a screw in stud you can pin a pressed in stud. Are you saying someone brazed the stud?

Vince

[junior stocker]

Originally Posted by BOBCRMAN@aol.com

Best way is to remove the broken stud. Then tap the hole for a screw in "repair stud". These are the same diameter upper but have threads that screw into the head. Any good machine shop should have them in stock or get them from Pioneer products, Champ, etc.

Like the man said, there are "repair studs" that look basically the same as a press in stud, except they have threads. There is no need to mill the stud boss. Tap the stud hole, a bit-o-locktite, double nut the stud, and screw it in till it bottoms out on the threads. Press in studs used to come in oversizes, but it sounds like someone broke a stud boss and did a redneck repair. The heat of that repair probably weakened your stud, and for whatever reason, it finally bent/broke.

[MrChevy]

Take a piece of 1" square bar stock about 3" long and on two good studs, find the center to center and center punch that spacing on the square bar stock.

Then, in the drill press, drill each one out to 3/8". Start with a smaller drill bit first so you keep the holes straight. Make sure it is clamped to the drill press table straight and true so the holes are perfectly straight up and down.

Then take a 7/16"-14 tap and tap one of the holes you just drilled.

Remove the rocker arm from the stud next to the broken one and slip the 3/8" hole over the stud and lightly snug a regular fine thread nut and spacers down on the good stud, with the threaded hole over the messed up stud hole. That is why you don't want to tighten the nut too tight... then take your tap and run it down through the end that you threaded and keep going a little bit until the end has went into the messed up hole far enough to lineup the tap in the hole. Then tighten the nut holding your jig down so it is snug and continue tapping the messed up hole.

You can look down in there after you take the messed up stud out and see how far you can run the tap down.

The new stud will have threads on both ends and on the end that screws into the head there will be a small jamb part that swells out about a 1/16".

You can buy one of those tap guides for $49.00 from Goodson. The drill press works fine to make one! Run your shop vacuum with the nozzle next to where you are working and it will suck up all the chips you make.

Put the special tool in your tool box when done and give yourself a slap on the back for a job well done!

NOTICE: There IS a chance they got the stud boss TOO hot when they brazed it. It so, the stud boss may be so hard now that it will peel the threads right off the tap. I've seen that happen with cast iron.

[F-BIRD'88]

The "370" casting SBC heads should already have screw in studs and guide plates.

If someone "Bronzed" (welded) the rocker stud boss to repair it from a previous mishap , this makes things much more complicated.

3973370....69-70...350..........over the counter in US, Canadian 350/300hp production use in Pontiac, 64cc, straight or angle plug

from Mortec.com

[327 / 350 hp]

Thanks for quick replies guys. I will check for proper stud to repair this. Does it have to be rocker stud for hardness. I would like to do this while eng is in car.. Yes vince somebody brazed the end of stud , to build it up i guess. Even so there is a piece broke off in hole..Think i can tap this to 5/16 and using slide hammer,remove it.. LATER jim

[BOBCRMAN@aol.com]

I seriously doubt if you can remove it with a slide hammer. If you are going to the trouble of taping a hole in it. You should just drill out the hole to size. Hardware studs will NOT work. Do it correctly.

[327 / 350 hp]

Thanks Bob This head is on the eng still. Dont want shavings in eng. Dont know if hole goes through...water jacket or intake runner. jim Orig studs are pres fit. Dont see why slide hammer wont work , Twisted the broken stud out with V-grips thanks jim

[327 / 350 hp]

Tried drilling out the stud with cobalt bit today, just polished surface. Its gotta go to machine shop for repair.. Somebody drilled hole and left piece on one side .How does machine shop locate center for rocker stud. THANKS..jim

[MrChevy]

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[327 / 350 hp]

Thanks all,, I have both valves out in the head right now.. Just want to make sure nothing is in way.. Do i need to strip head totally jim

[327 / 350 hp]

Machine shop couldn't //wouldn't replace broken stud!!!!!!!. I have arc welder and ox/acet. any ideas???? thanks

[S10 Racer]

Originally Posted by 327 / 350 hp

Machine shop couldn't //wouldn't replace broken stud!!!!!!!. I have arc welder and ox/acet. any ideas???? thanks

With the stud broken off down inside the hole, I don't think you will have much luck getting it out. The studs are hardened and very hard to drill. The only idea I have is to find someone with a stud welder and see if they can weld a stud on it for you so you have something to get ahold of to pull it out.

[327 / 350 hp]

Well i had to send the head to machine shop for repair... Guy said it will take a while... I have a set of #462s with no valve springs. Eng is 350, flat pistons,rams and 650 Holley. Just a stock mill. Cam is HiPo 327.. 447 lift 306 duration.. My install height is 1.880. Any ideas on springs .... thanks jim