New to Pontiac's.
I am going to replace my headers with factory logs. I see a cone shape taper in the casting where the bottom of the manifold meets the down pipe ( between the two studs). What if that tapered casting is partially rusted and not a nice smooth surface? Is there a flange that is supposed to go there or some kind of donuts like on my Chevy?

1. How do you seal without any leaks between the manifold and the down pipe?

2. Do you use the nuts with springs?

3. Do you recommend factory type metal gaskets between the manifold and the head? or is any aftermarket type ok?

4. What size and length are the manifold bolts? I only have the little header bolts