Broken (3 corner) Header Bolts
 

Finally developed a leak at #8 cyl. so it's time. Didn't know about them for a long time. This 400 has long tube headers. So I figure the engine comes out or the heads come off. Has anyone tried leaving heads on, applying heat, welding up bolt material to get them out ? My concern is head or head gasket damage (warp, leaks). My former machinist brother says heat the bolt cherry red, build up bolt if needed, let cool to black and put a bean size piece of wax to wick into threads. Never had one he couldn' t do.

Another way this guy I worked with did them was drill a pilot hole big enough for a small torx bit hammered in. These bolts are most likely the originals from the cast iron days. Question 2 : Anyone know if Pontiac used grade 5 or 8 ? The 8's may be a problem drilling.

Sure miss my old Z28 header bolt access :). Thanks for any help.

Neil

Just about every SUV, Van or Pick Up truck with a V8 suffers from broken exhaust studs. Guys are drilling them & torching them all day every day in shops everywhere so don’t worry about drilling them or even heating them up with a torch, a cast iron head & block can take a lot of heat before you’ll affect the head gaskets, etc.

I would remove the header on that side by jacking up the engine so that you have a good shot at the studs, you may luck out & have a piece that you can grab if it snapped flush to the flange, if not maybe you can grind a flat into the stud & use a screw driver to get it out or drill it out & use an EZ out or finally as you suggested a quick weld to attach a bolt to the snapped stud. They suck to get out either way & a Pontiac head makes it worse due to the angle of exhaust but it’s doable with enough patience. If all else fails at least you can pull the head & do it on a bench but I’d try every other option first before I pulled the heads or motor.

I did the broken bolts on my drivers side & they are a grade 5 bolt, actually came out pretty easy once I got them moving.

Thanks for your hands on advise. Since the are all corner bolts, jacking may just allow room after removing the headers.