Std. oxy/acetylene cutting torch, w/a smallish focused flame, keep pulling back if the edge starts to look like it's about to melt, maybe 10-15seconds or so it should be glowing
bright orange. In the case of my ancient Ford manifold, it took a while longer in totality, not a job for the impatient for sure. The other stud I had to weld a nut to the end, and
go thru the heat process numerous times before it broke loose, I also had to fire the broken stud w/a torch before welding the nut on to get a satisfactory weld. Sucked in the
truck, but if you think I was going to start taking all 8 of the 60yr-old manny to head bolts out.................:rofl::rofl: