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
Head pipes mate with the manifold with no gaskets. Clean up the spherical surface the best you can. Get the studs and nuts from Ames Performance, no springs. In fact, get all your parts from Ames Performance. Get a set of manifold bolts from Ames. Exhaust manifolds are not all the same and some have different length bolts so make sure you get the right ones. They are hardened bolts.
Ames is in Spofford, NH near Keane. Not sure where you are. You can order parts and pick them up to save shipping. Maybe show up there with your manifolds and they will hook you up with the right bolts.
All good advice from Bob S. The only things I would add is to make sure you have the right manifolds and generation of f body manifolds. 1st gen. f-bodies use a rear outlet on the pass. side and a center outlet on the drivers side. If you have the wrong ones you can rough fit them and see if you have the room for a custom bend pipe. I always use high temp rtv on all my exhaust connections especially the manifold ball connection. When buying the hardware make sure and get the brass/bronze nuts. And lastly use high temp nickel anti seize on all bolts and studs and make sure you coat not only the threads of the manifold bolts but also the whole length of the shoulder as most manifold bolts rust/seize in the manifold and not in the head. p.s. make sure and look them over really good for hairline cracks before investing any time in them.