Upper Intake Manifold Repalcement

**GPCharlie** · 04-04-2015

For those that have done this what aftermarket or OEM upper intake manifold would you recommend using? I'm looking for longevity. Replace it once and be done with it. I picked up a Dormans, but before I use it I want to know that it will stand the test of time. If there is something better I'd appreciate knowing. Thanks.

**Pontiac Racer** · 04-04-2015

I think you can swap a Series III on there? Someone correct me if I'm wrong, but I feel like I've seen or heard people do that. Those are metal so they won't warp and never have to worry about them, but I'm not sure if it can be done.

**Fivefingerdeathpunch** · 04-04-2015

Dormans work just fine, have one on the sisters bonneville for over a year now.

It's what we buy at my work too.

Hopefully you are doing the lower intake gaskets at the same time.

**GPCharlie** · 04-05-2015

Absolutely doing the lower intake gaskets at the same time! Want to get rid of the junk plastic ones that are there. Will also replace the plastic bypass coolant elbows with aluminum ones, new t-stat and o-ring, and new o-rings on the fuel injectors. Anything I've missed? Thanks.

**BillBoost37** · 04-06-2015

If you want your manifold to last, here's the info that most don't realize about why there's an issue.
http://www.grandprixforums.net/threa...hlight=failure

Personally..I don't replace the manifold. I modify the LIM to plug the coolant ports. Then the issue can never happen.

**GPCharlie** · 04-06-2015

Well Bill, that does sound like the way to go to preclude that from ever happening. No coolant to the upper, no leak to the lower. I guess that is what I should really be looking at doing. I'm in Southeastern Mass, so if you haven't had problems with icing being in the Springfield area then I shouldn't either. And I never have to worry about a coolant issue from that area of the car, ever. Sounds like a winner. Thanks!