Having discovered a blow on the nearside joint from the downpipe to manifold, I got a new gasket for it and squirted a liberal amount of liquid spanner on the bolts last night. This morning I squirted a bit more and let it soak in while I had a coffee...then the first sheared clean off and so I tried the other, and now both are sheared!

Am I going to have to replace the manifold as it's not in the easiest place to get to to drill them out or does anyone have a solution for such a problem?

Thanks

Mine broke off exactly the same so i dad to take the manifolds off completely to be able to get some heat on them. there could be enough thread sticking out the back to grab hold of.
got mine red hot then they came out easy.
while the manifolds are off check for usual cracks where all 4 pipes meet. mine needed re welding.
good luck

Managed to beat a few clamps with the birmingham screwdriver into a weird shape to secure the 2 sections together to get me through tomorrow.

And ordered a pair of stainless tubular manifolds and new gaskets all round. Just need to find a suitable replacement for the rest of the system now.

Thanks for the response though John!