Might check SOR, IIRC I picked up a couple of manifold studs from them for my 40. But that was a long time ago. If you have one available you might try Austin Bolt off Metric,.
Kenny have you sprayed along the top and bottom of the intake manifold where it mates to the head? It's kinda tough to get to the bottom side. Be careful doing this, have an extinguisher handy, I did it before the engine was warmed all the way up because I was worried about a fire, but that's...
I can lend you a vacuum gauge if you dont have one so you can get a reading at idle. I live the 2F world so I may not be the best source of info on your machine, but it really has helped me in the past in tuning my carb and setting optimal timing.