The BV8 cast manifolds had a very thin flange on the downpipes. There were three studs on each manifold and when "overtightened" would break the casting. I believe that towards the end of production, the flanges were thickened. I fitted a pair of Janspeed stainless manifolds to mine at the rebuild. It needed half an inch of panel bashing to the inner wings for clearance. Before that I repaired both the cast manifold flanges with JB Weld and amazingly it lasted until the rebuild, about 12 months, without letting go.
