PontiacBonnevilleClub.com

Hey guys i picked up at great deal on a set of speed daddy headers for my car and before i just jump into trying to bolt them straight up and getting aggravated over and over again, i wanted to come and ask you all for what i need to do and have to make this installation go as smooth as possible so if you could give me any incites on what i will be dealing with that would be greatly appreciated!

I look forward to reading your wisdom and knowledge that you have to share or your past installation to make this an easy swap for me.

I'm not too keen on the specifics on installing them on an H body, but I'd recommend taking out the rear plugs beforehand as it's easy to crack them. And get some Felpro gaskets and band clamps as well.

rear plugs do you mean 02 sensors if so i plan on replacing them with fresh ones so that will be no issues

Spark plugs. It'd take some talent to crack an O2 sensor! Which reminds me you will need extension harnesses for those. I made my own because I'm cheap. Make sure you get AC Delco or Denso if you want it to last.

Why do I need an extension harness and okay thanks for the heads up on the plugs didn't even think of the small stuff

The stock harness isn't going to reach down to the new location of the front sensor. The rear one might but the rear did not reach on my GP.

Where would I get an extension rock auto maybe?

Zzp has them. I went to the junkyard and snagged both ends of the oxygen sensor plugs along with a few inches of the wires on either end. Then I spliced the ends of the wires together and boom, two extensions for under $10. I wrapped them with electrical tape and put some loom on them to protect them.

Great idea that's exactly what I'll do as soon as the mysteriously hard to find Bonneville reappears at my local junk yard!

You will also need to either get a transmission dipstick from a Grand Prix/Regal or bend your transmission dipstick (I tried to and kinked mine so I got a w-body one from a junk yard for a couple bucks).

I'd also recommend getting a new flex joint (ZZP also has these), because the one Speed Daddy uses is crap. They're almost guaranteed to blow and have an exhaust leak. I had to weld up a cat when I did the headers so I took it to a shop open header to have that done. I also had a new flex joint with me to have them weld this in while they were there. The guy talked me out of it by saying normally people install them and don't have them in a "neutral" position so that there's no force acting on it at all times and he said they'd make sure this was done and it wouldn't be a problem. I took his word for it and let it go. Here's what the flex joint did later on. .

The other thing I recommend is using these type of band clamps for the crossover connections. It's been hit or miss on exhaust leaks from the crossover tubing. In my case the rear connection sealed fine but I'm nearly constantly fighting an exhaust leak on the front connection.


I was able to get away without the O2 extension, I undid some of the wire looming to allow it but it's still definitely a stretch.

Unfortunately, these are cheap for a reason...they're cheap quality. But with that said, you still come out way ahead of other header options if you fix these issues.

1. What year Grand prix im heading to the junkyard Friday and can pick one up.
2. so i will have to cut the old flex joint out and get a new one welded in?
3. and i was considering getting it all welded together so what would be the cons on doing this?
4. any good advice for doing the rear?

DON'T use FelPro exhaust manifold gaskets -they are paper and will blow out in a very short time.
Reuse the factory multi-layer steel exhaust manifold gaskets and you will have less problems. If you insist on getting new spend the extra $ and get new ones from GM.

Well I'll have to get new because my factory ones are worn out

I did not know that about the gaskets. I got the Felpro ones since my stock ones didn't look so great. It's been almost two years and still no leaks. I'll be watching for leaks once I start driving the car again.

The trans dipstick from 97-08 should be the same on the W body cars.
As for the flex joint, I have seen many of them fail so it would be easier to have it replaced now before it goes on the car. I haven't replaced mine yet but I'm going to wait till it fails.
You could have them welded together, but if you ever have to take them off for any reason they will have to be cut off at the crossover.
I don't know if its needed on a Bonneville, but on the Grand Prix I had to unbolt the dogbone mounts and hooked a ratchet strap to the rear lifting point on the engine and the other end to the core support to tilt the engine forward to get more clearance at the rear of the engine. I'd imagine if you needed to do this on your car you would have to loosen the trans mounts to achieve this since you don't have the dogbone mounts.

so i may have some time on the flex joint before it fails that's good news but i still may replace it seeing as how its only 11 dollars to do so and removing the front transmission mount will hopefully give me enough clearance

I think I have just come up with an amazing idea what if since I'm throwing away all of the old factory Exhaust, what if I cut and removed the old factory crossover connectors and had them properly welded into the new headers the only downside I see is how would I repolish the old parts to make them look closer to new and a smaller perk to the unknown they would look factory which builds into my sleeper look.

Does this sound feasible?

Double posted for some stupid reason guess because i was on my mobile device

Won't work.

I would weld the crossover to the front header, and clamp the crossover to the rear header. I had issues with the crossover not being bent quite right, had to cut and re-weld it, fixing that will help prevent the crossover joint from leaking:

MattStrike wrote:Won't work.

Ok Matt just curious not saying anything about this statement but, could you please elaborate on why this wont work? I thought that if i cut a little back from the connecting brackets on both sides were they bolt together they would make it work like factory crossover, is the pipe diameter different and if so im sorry i didn't know . Was under the assumption that only the down pipe increased in size?

No space to fit a flange on the rear crossover joint, and don't need the front crossover joint at all, may as well just weld it (reference the ZZP header design). If you can weld, no point in not fixing the crossover not being bent correctly, once that's fixed all you need is a preformed lap joint clamp for the rear joint (like this): http://www.amazon.com/SmartParts-100225 ... B0043DOTE8