I worked it in groups and stages. I started at the baggy end(the back,for me). I snugged the back 4 bolts; tightened them lightly with a wrench, in an X-pattern,about 3 times, ever snugger.Then snugged the center and front end;lightly. Then another X on the back;to 60%. then X-patterned the front to 60% or so. Then X'd the back to 80%. Then the front to 80%, Then the rear to 100%. Then the rest to 100%.Or some such a thing.
I thought the important thing would be to not pull one side of the back tighter than the other, and to allow the manifold enough flexibility at the front, to allow the rear bolts to draw the intake down into the valley.
Seems to have worked.I've never had a leak since.
In fact, my 230* cam will idle down to 500rpm in starter gear of 10.97,pulling itself over soft ground.Then I pedal the clutch some, cuz, if it falls much lower it will probably stall.