For anyone that cares if you after a set of longer exhaust manifold studs in M8 x 1.25 go to BMW and ask for a set of studs and nuts for a BMW E28 528i they are perfect for the job about 10mm longer than standard cossie ones plus but still have good length that goes into the head (which you don't get on many studs) Plus 16 Nuts and 16 Studs only came to £21.78 from Sytner BMW in Solihull.
Rich