shaker hood

[Carboy57]

I am restoring a 1976 Trans AM for a client however to make things more interesting it has a 77 hood and shaker scoop on it now. Now I believe that the base part of the air cleaner is still the 1976 one.
My question here is this, are the two different? When I mount the shaker to the base there is no way that metal ring tightens anything. I cant find any diagrams showing how exactly it all hooks together.
Can anyone help me or guide me to putting this puzzle back together again ?

 

[melsg5]

looking at the aftermarket reproductions the 70 to 76 use a different shaker scoop than latter years and looking at Ames they totally skip over 77, their next range is 78 to 79. Their Firebird catalog has some diagrams of how things go together.