Help! 5.7 exhaust manifold differences?

[Bkjmak]

I have a 1984 C30 5.7 with a manifold exhaust leak.
When removing the manifold I realized that the last manifold bolt was missing. I assumed it had fallen out, but on closer evaluation, the manifold didn't fit the head. Didn't have a bolt because it was the wrong manifold.
See pic.
Looking at the attached picture, you can see the gasket was designed with two options for the back cylinder. My manifold was designed for the outside hole and my engine it designed for the inside hole.
Does anyone have an idea what the difference is and what kind of manifold I need to purchase?
Brad

 

[72velle]

Since you already have the manifolds off I recommend the Hooker manifolds below:

Pardon Our Interruption

I have these on my 84 with a 350 and I like them.

 

[ali_c20]

Since you already have the manifolds off I recommend the Hooker manifolds below:

Pardon Our Interruption

I have these on my 84 with a 350 and I like them.

I have them on my C20 they fit like a glove.

 

[idahovette]

Yep, those Hookers are on my 75K20.....work great!!