manifold removal

[yamaha537]

Im starting to dissemble my truck for my s472 to go on. I got the up pipe bolts on the turbo and the passenger side up pipe to manifold bolts off. They were a HUGE pain. I ended up snapping a bolt in the manifold and figure ill take it off to drill it out. And ill be doing a LML drivers side.
The manifold bolts look pretty crappy (NJ salt) and im just looking for pointers on removing them. I really don't want to end up snapping one in the the head.
Ive been soaking them like crazy in PB.
Should I hit them with an impact to break them free? if they are anywhere as tight as the up pipe bolts, anything by hand will suck. the heat shields are mostly rotted away so I don't have to worry about that too much.

 

[clrussell]

See if they come loose by hand, every manifold bolt to head I've pulled came right out. Up pipe bolts are another story though.. I break one on just about every truck. Last truck I broke 5.

 

[BLACKMAX1]

The driver side on mine I was able to put an extension on a 1/2in breaker bar and they came right out. Yours sound pretty corroded so a lot of PB soak time will help. Could try to heat them up with a torch if your feeling ballsy.

 

[andy-stevenson]

I'd just use some pb blaster and they should come out fairly easily. I'm just tearing apart this engine I bought and snapped one of the uppipe bolts but the manifold to head bolts came out easier.

 

[ikeG]

Some of these rusty trucks, there really isnt much left of the manifold nuts or bolt heads!

 

[BLACKMAX1]

Just remembered you can hit the head of the bolt with a punch, send some vibration through it. Helps with the stubborn fasteners on the aircraft I work on.

 

[yamaha537]

Well I soaked the crap out of them in PB blaster and they actually weren't horrible to take out to my surprise. Just used a breaker bar where I could.
Snapped another up pipe bolt but it's getting a LML manifold so no big deal