Exhaust Manifold Rear Bolt

I am removing the exhaust manifolds on my 68 Barracuda. It has a 69 HP 383. The manifolds are stock.

This is my first real experience wrenching on my own vehicles and you guys can probably guess what happened. After I was done cleaning up the mess, I started digging and apparently I can't find the right Google search words.

Why is the rear bolt hole for the exhaust manifold inline with the coolant system inside the block? Was there a purpose for doing this?
Author: admin