Hello all,
I've got a question about dual exhausts. My '76 came with a single exhaust like most did. I would like to put dual exhausts on it. Upon looking underneath the car, I saw that the transmission shift linkages are right in line with where a left exhaust pipe would traditionally go. I know there are double hump crossmembers on the earlier cars, but I'd like to avoid replacing that if possible. Could I run the pipes closer to the outer edges of the frame? How have you guys run your pipes?

Thanks

 

The equalizer rod from the frame to the trans is the same part number from 1973-1977 on the A-body cars, and dual exhaust was a factory option in 73-74.

 

Go to a good muffler shop and they should have no problem installing duals. I think it will be very difficult without the double hump crossmember.

 

I was afraid of that. I don't have a lift or even a transmission jack to hold up the trans. while I swap out crossmembers. I'm working out of my garage, so I don't have access to a lot of air tools.
Are the crossmembers bolted in or riveted in? I think on my pickups they're riveted in.

I was hoping I'd be able to run the exhaust pipes along the frame rails, but maybe that's not advised.

 

All you need is a normal floor jack and a short piece of 2x4. You're not removing the trans, just lifting the back of it enough to take the weight off the crossmember. The crossmember is bolted in - it has to come out to remove the trans. And you should plan on running the pipes exactly where the factory did on the 1973-74 dual exhaust cars, which is not along the frame rails. Don't overthink this. GM did all the engineering for this almost half a century ago.

 

Thanks for the info. I will see if I can locate a double hump crossmember locally.

 

Pm me for a guy in Iowa that may have some parts for you, I’ll give you his info. I know he has several years of different parts, he may have one for you.
eric

 

If you are taking the car to a exhaust shop for a factory type dual exhaust, (which is what I would do also), why not just get a dual hump crossover and ask them to install the crossmember while they are bending/installing the dual system?

 

That is a good suggestion Greg. They will have it on a lift and it will be easy for them to do. It will save you a ton of frustration. It might be a good time to change the transmission mount.

 

Those are great suggestions. I think that is the route I’m going to take.

 

G-force sells dual-hump crossmember for your car, and Summit aswell. Atleast on some point the Summit crossmember was actually G-force, just cheaper. Go figure.

You need to enlargen the bolt-holes at frame a bit, but otherwise its a bolt-on deal. And its not touching shift-linkages / anything if factory-routed. That is, if you cant locate factory dual-hump crossmember, or dont want to fabricate your own.

 

You will need anew intermediate parking breaks cable because the one you now have is too short . The 74 cars use a 106 inch cable which will work well to be able to use the parking brake !