Walker catback for 3.8

[clean8485]

As MeanBuicks has said, you need to make sure that you have the proper hangars in place to support the extra parts, and the extra weight of that style of exhaust system. Another issue that you will likely run into, is the style of the flange that attaches the exhaust pipe at the back of the catalytic converter. Most of the higher performance G body cars that came from the factory with the dual style exhaust system that splits behind the catalytic converter, were equipped with a lower restriction "monolith" style catalytic converter, that has a wide flat oval style opening, with a flat 4 bolt flange, with a matching flange on the exhaust pipe to attach the 2 pieces together. If you purchase the turbo Buick exhaust system, it will likely have that style of attaching flange on the exhaust pipe, which means that you'll either have to modify the exhaust pipe to fit the original catalytic converter on the Bonneville, which likely has a 2 bolt "ball" style mounting flange, or replace the original converter with a turbo Buick style converter, in order that the cat-back pipe will bolt to it. If you change the converter, then you may have to make some changes with the exhaust system ahead of the converter, because usually, the monolith style converters have a larger inlet diameter than your original pellet type converter, which means that the exhaust pipe that comes from your engine will be too small to fit it, or, in the case of the Monte SS converter, it has the large oval 4 bolt flange on both ends of the converter, which won't work with the exhaust pipes on your 3.8 Bonneville either.
At this point, you have to kind of step back, and try to judge whether all of the work and expense to convert your mostly stock original 3.8 Bonneville to this type of exhaust system is really worthwhile. As I've said before, if your intentions are to keep the car stock, or close to it, then I don't believe that the expense and trouble to install this type of exhaust system on the car is worth it. If you are going to modify the car for more performance, or eventually install a larger engine, then this type of exhaust system is a worthwhile upgrade, but not so much on a car that is staying pretty much original.
In my opinion, your best bet would be to install a cat-back system with the single exhaust pipe, and the dual outlet muffler and 2 tailpipes. Its the easiest, quickest, and probably the cheapest route to go for your car, and for what you're looking for. At most, you'll probably have to install an additional hangar on the left side at the rear, to support the additional tailpipe.
Sorry for the long-winded post, but sometimes, changes can have a domino effect that can cause extra expense and aggrevation, when its not anticipated, even with the best intentions. Good luck with the car.

 

[clean8485]

Another thing to consider, is the type of material that is used in the exhaust system. Try to find a system that uses a heavier gauge of steel, or steel with an aluminized coating. Because these cars have the muffler at the rear of the car, and you live in an area which is prone to rust, the mufflers tend to rot out more quickly. During my time at the muffler shop years ago, we replaced alot of mufflers on these cars, while the exhaust pipes were still in good shape. The muffler was the last part of the exhaust system to heat up, and the first part to cool down, and if you don't drive the car much, then alot of moisture will build up in the muffler, and cause it to rot out more quickly. Hope this helps.

 

[MeanBuicks]

If you're interested in pursuing the premium options look into Pypes and RJC. Those are stainless. For aluminized, look into the Hooker system. Pypes and Hooker are available through Jegs or Summit Racing.

 

[Plain Jane]

Great write-up clean8485, that's some good information I'll put to use. By what you've written the V8 catback will be much simpler to install as I'd only need to fashion an extra hanger? Converters and pipe diameters are the same between NA V6s and V8s?

I'll take a look at the aftermarket stuff too later tonight. Thanks.

 

[clean8485]

I just finished some checking on the Walker exhaust website. The site lists the single exhaust pipe, dual outlet muffler system for late '70s and early '80s Monte Carlos, Malibus, and El Caminos. The Walker site lists part numbers for the cat-back pipe, and both tailpipes, but it doesn't list a part number for the single inlet dual outlet muffler. I'm not sure why the muffler isn't listed, while the rest of that system is listed. The muffler may be available from another source. Do not use the cat-back pipe for an El Camino, as the El Camino has a wheelbase that's about 6" longer than any other '78-'88 A/G body, and that's reflected in the extra length of the cat-back pipe for those vehicles.