Do all Buick bellhousings have 2 starter openings?

Is this one an aftermarket? Did factory bellhousings only have one? I assume it's because they are also used these on Olds and Pontiac? Thanks

 

The Buick bell only has one starter opening. Olds and Pontiac have 2 openings. But they will work on our engines

 

Thanks guys...If I "cheap out" and this ends up going in a beater or daily driver with a 455, will that driver side starter opening get in the way of headers or clutch rod and stuff?

 

Nope

 

I think with a file a can turn the 8 into a 3