00' B1500 exuast manifold broken bolts

I have a 1998 B1500 with 86k on it in good shape. The truck runs good except for the leaking exuast manifolds. They are leaking and they overheat and melt my spark plug wires after awhile. I use the van for work on weekends only so Ive dealt with this problem for awhile and just replaced the melted plugs from time to time. I ordered up some manifold gaskets thinking this wouldnt be too bad of a job, maybe some stuck bolts maybe ill get lucky. needless to say someone else had this problem and gave up...but after breaking off 3 bolts and leaving 4 extremely rusted and stripped bolts. i soaked the bolts and used a brand new heavy duty vice grip with no luck. i even ran the truck for awhile heating them up with no luck. even tried a propane torch and no luck. i guess i see why the previous owner gave up :banghead:
anyways im trying to figure out if its worth pulling the heads and fixing this poor van right? how hard of a job is this on this v6 van? doesnt look too awful but i figured id ask someone with experience before i go yanking stuff off and end up with a large storage locker. im fairly experienced but more with classic easy to work on cars. ive done head gasket changes before but on nothing newer than a 1966 ive done intake manifold on a 95 astro van with a v6 with no problem.
is there any other way to do this without pulling the heads or my hair out?
on the bright side if i do pull the heads i can give them a nice valve job while they are off....just not sure if i want to take on this or not....advice or suggestions gladly appreciated

you need an oxy/acet torch to heat the heads around the bolt fast enough to help and stud removing socket work better than vice grips.

it works, i've done it often enough, but there is a definite risk of fire so have an extinguisher handy!!!

Im going to try that. i actually didnt own a extractor set so i just ran down to the local pep boys and grabbed a irwin/vise grip brand set. ill give that a shot tomorrow. worth a shot...thanks...any other advice greatly appreciated

just heat the head around each bolt for about two minutes trying not to heat the bolt, then spray penetrating oil directly on bolt only, to cool it. grab with vice grips or whatever, if it is not broken or stripped us a socket and they should come right out.

several layers of heavy duty aluminum foil makes a good heat shield.