Extract exhaust bolt: weld nut or drill?

[Boogle]

Hi guys,

Removed my exhaust manifolds from my 2000 986 2.7. Despite liberal use of care, time, penetrating fluid, heat, etc, I managed to break off 4 of the bolts. All are sticking out 3-5mm from the surface.

My question is, should I try the weld on nut technique first, or go straight to drill-out with a jig/kit?

I’d like to try the welding method, as there’s a chance of getting 1 or 2 out with little time spent, but I am worried about warping the head or something. Can I do this with a stick welder, or would MIG or gasless MIG be less risky?

I’m of course planning to take it easy - attach the nut, let it cool, build up some more weld in the nut, cool, etc. But, the whole point is you get at least some good heat in the stud/head, else it won’t work. The “MAP” gas I’ve been using obviously was not getting things hot enough to break the bond between rusty stud and head.