What you need to know is that if you break a bolt off in the head, you are going to pay h3ll getting that fixed. Two methods I have heard of using or have used myself to get them loose: Heat vehicle up to operating temp, then try to remove any stuck bolts...they will be corroded and weaker than when new, so don't go being a guerilla or they will break. I use a 3/8" with a handle that doesn't give me enough leverage to break the bolts unless I really try hard. The other method, which I have used with much success, is to hit the bolt head (if accessible) with a hammer, repeatedly, and hard. Works the same as heating up the surrounding metal.
One thing I JUST thought of. Since heating up the surrounding metal, but not the bolt, is the best way to remove a stuck bolt, bringing vehicle up to operating temp will help, but won't be the best. Now, I know that the "canned air" stuff they sell for computer cleaning, is propelled (I'm almost positive) by propane. As it comes out, it is very cold. If you turn one of the cleaner cans upside down(its really neat lol) you can in short order, freeze a small quantity of water in a plastic cup. Watch your fingers though, the nozzle tends to drip freezing liquid. So my idea then, is to heat vehicle up to operating temp, hit bolt head with hammer a few times, turn vehicle off, spray with the freezing stuff, then wrench it out.
The stuff isn't liquid nitrogen, so you won't have to worry about the bolt shattering because its cold. It just might do the trick. If you ask me, any bolts on a motor that is still in a vehicle, that don't easily come out, are worth EVERY precaution against breaking them off. An EZ out in almost all cases won't save you either, since more than 50% of the time break off themselves. (think about it...an EZ-out EXPANDS the bolt into the threads as it bites into them)
Also, use BRASS nuts on the new exhaust manifold studs, as they will not get stuck on the studs like steel nuts will. You'll probably break the ones on your truck now off trying to remove them. No biggie of course because the manifold is garbage, but on a good manifold, you need to heat the thing up with a torch to remove them.
Anyway, some thoughts.
Dorian
My K5 and Chev/Olds tech/links page: <A target="_blank" HREF=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</A>