customer has some dart big block heads and it pulled the studs out of the jesel rockers some can be helicoiled the others will need to be machined and welded . Now The engine builder said Dart does have a special rod for this that they have cast for this purpose has anyone heard of this . also with being the bosses for bolts and has to be threaded after My first choice would be 5356 over 4043 as I feel the threads would be stronger or am i wrong to assume this for most normal repairs im sure 4043 might be the rod of choice but I need as much tensile strenght as possible ps only ppl that have actually done this repair respond . Thanks Dan. also Im assuming I shouldnt use preheat to maintain the integrity of the cylinder head and try to keep as cool as possible during welding ?