Need advice or tip to remove those 16mm bolt near the spark plugs. Can that be damaged or snap if we use a strong guy to wrench it off? Thanks

 

I don't recall having to undo anything that large. Can you give any better pointers as to the location?

 

There are 4or5 of those right beside thr spark plugs. Probably 15 or 16mm. Very tough to turrn. It wont get loosen at all.

 

If you are talking about the exhaust manifold bolts.... yes they can break. Heat and penetrating oil helps. 1st take 2 shots of Tequila and have at it.

 

i think the head stretch bolts themselves are being referenced in this case. They appear to be about 16mm in size to me.

 

These near the plug and the one on the far left of picrure. Ty

 

Those are the head bolts. They will be tight but should come out with hand tools. Remove the valve covers first though, the other 5 are under the rockers. Here is the removal sequence for the driver side.

 

remove the spark plug and the SAI pipe in the head(18mm for SAI pipe).

 

Yep, those are the head bolts. STOP WHERE YOU ARE, and don't try turning the ones you have exposed until you have removed everything under the rocker covers and everything down to the lower plenum as well.
The head bolts need to be removed carefully, in sequence, turning just a few degrees at a time especially when you are initially trying to crack them loose.
The RAVE explains all of this.

 

Those headbolts are 5/8". Read other recent threads for advice. Like said above, remove valve covers and rocker assembly first.