OK I did a search and there is a lot of opinions on Dual Exhaust systems; some members had an easy conversion and some I read sound like horror stories. I currently have all the factory AIR Pump equipment pipes on the factory exhaust pipe and there is what looks like a Damper right after the Manifold on the Passenger side; there even looks like an actuator on it. Can anyone tell me what that is? Do I need it? I want to keep the factory AIR pump because I really will not gain much by taking it off

Also, I’m torn between having a custom Exhaust made of trying the Do it yourself method on the Mid America system. I’m in the Detroit Area has anyone had a good custom made around here?

I want to do the exhaust right the first time; any opinions or suggestions would be greatly appreciated!

 

That is part of the emissions, no you don't need it. The AIR pump steals about 10hp, so if you can get by emissions testing, lose it, It is also there to support the CAT and if thats gone with the duals you don't need it.

 

I just might have to put it in a box in the attic! I've never going to sell the car so all oriignal really does not mean much to me! Hell if I had a larger garage I would moth ball the L48 all together. Would a 572 fit?

 

I always install my own, but Doug's Muffler in Mt Clemen's does good work and has a huge following if you are in that area. Be specific about what mufflers you want installed. Call any shop first to find out if you need to remove the cat first for them to install dual exhaust.

The only mod to put duals on a '75 is to remove a dimple from the front exhaust hanger on the LH side. GM put a dimple in the hanger to prevent an exhaust pipe going through the LH crossmember hole. Remove the dimple and the pipe will fit and clamp perfectly.

 

My sentiments exactly (actually, I DO plan to mothball my L-48 for a BBC)! Being from the Detroit area, where do you go for aftermarket parts? Any good speed shops just north of the city? I'm just across the (St. Clair) river from Algonac, Michigan.

 

My L48 is taking up space as well. If you remember Ramchargers Speed Shops, they went out of business. 2 of the locations are now under new ownership and called Detroit Speed Shop (14 mile and Gratiot). Also, Lucavich on Gratiot north of 21 mile.

 

I know of a couple speed shops; Pande Performance in Livonia, Livernois, and Lethel in Taylor. Never had any work done but I think Pande is going to install my Sub Frame on the Cobra.

ahoover; I did not know that ramcharges was under new ownership. The one in Livonia is still a vacant building; maybe they will come back also.

I think I'm going to call Allens SS Exhaust for the True Duals. I've heard good things. Anyone have experience with their systems on a 1975?

 

I installed an Allen's 4 muffler chambered system (aluminized) on my '75 last year, sounds just like the old factory sidepipes. Two friends have since purchased identical systems. Everyone asks what the exhaust is. I did a lot of research and found Allen's to be the best choice.

 

Going to place a call to Allens. Thanks

 

Make sure you have someone who will pass it through inspection after you change; if they go by the letter of the law, your exhaust has to be in it's original config. I know it's BS, but it's the federal law...

 

Not in Michigan; car is too old to even need an inspection. Registration is good until 2010!