Is it the one on 1,3,5 &7 bank.. the one with least amount of room ?
the downpipe bolts I used a dremmel on to cut a wedge out of the nut then a cold chisel to open it up. Wen the manifolds came off it took heat and big stilsons to get the double ended bolt out. Of course if you take the manifolds off you've got the joy of the heat Shields and lower exhaust manifold bolt on number 7 to contend with.
Tip: get a bigger swear jar!