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Discussion Starter · #1 ·
i have 2 questions, first off i want to install a dual stainless exhaust but when i called my exhaust shop they told me the only way for them to do it was they had to notch the frame, is this necessary. Secondly i also bought a set of z28 5 spoke rims and wondered what kind of cheap and good performing summer tires i can possibly get.

Thanks.
 

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it is sort of neccesary to notch it. i have an 85 2dr and i have dual three inch exhaust in mine. its not the frame you have to notch it is the transmission crossmember. we took a piece of angle iron and welded it to the top of the crossmember on the drivers side. then cut out the tubes on the bottom and boxed in the holes to strengthen it. this gives you ample roob for three inch pipes. but, you wont be able to take three inch over the rear axle. you will either have ro neck it down to 2.5 or just dump it in front of the axle..

 

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a 94-96 b-body crossmember can be adapted to your car, which had provisions for dual exhaust. you can also route both pipes around the passenger side of the crossmember.
 

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a 94-96 b-body crossmember can be adapted to your car, which had provisions for dual exhaust. you can also route both pipes around the passenger side of the crossmember.
That is a simpler idea for the left side exhaust already cross under the oil pan to the right hand side.
 

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Discussion Starter · #5 ·
I really don't want to start cutting under the car, will routing the exhaust on the left side cause any problems or will it be fine? I don't really need to worry about the size of the exhaust it's not going to be very large. I plan to leave the motor stock accept for a dual snorkel from a 305 H.O. and the exhaust.
 

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You will have to crawl under the car and see just how much room you have between the floor of the car and the top of the cross memeber. There may not be enough room to put the cat for the left exhaust in on the left side.

Or you could go ahead and route every thing on the right side up to the axle and then come over the axle and out the left side.
 

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Discussion Starter · #7 ·
I forgot to mention where i live after the vehicle reaches 20 years of age it doesn't have to meet any emissions requirements so i decided not to install any cats at all and save me a bit of money.
 

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In that case there should not be anything to stop you from running the pipes down the left side of the car. Just be sure to not get to close to anything with rubber lines or use heatshields.
 

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This is even later, but I don't have a solution, just the same problem.

I want dual exhaust on my 78, but the crossmember does create an issue. How much does a double hump crossmember cost? I'm starting to think I will have to go single anyway just due to the expenses. Plus, I can't seem to find a local shop (portland, OR metro area) that will do it without a cat. The car is emissions exempt, but apparently that doesn't matter, and apparently these shops don't like money enough to work with me.
 

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Its not that they do not want your money, they do not and will not pay the fine for tampering with a system that was required to have the cat when the car was manufactured. Some of the fines run as high as 10K and nobody and I mean NOBODY wants to put in a few hundred dollar for an illegal exhaust system that can cost them more then they make in fines.

Though our cars are not required to pass the emission test they ARE required to have all the emission systems in place and operating, other wise the owner can face paying up the fines if the vehicle is caught without the systems in place and working. I learned this in the state I am in and I do believe that all states have a similar law as well. You can thank the EPA for that one.
 

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well first off check into your local laws to see if they have 2 things decibel reader for loud exhaust and 2 do they check for emissions on older cars. When i lived in nd none of the cops where smart enough to check if i had a cat they always pulled me over for being to damn loud lol. headers is one of the first things i would do, secondly flowmaster makes some really really nice mufflers that are 50 state legal u can buy them at jegs,summit..etc. A flow though cat u can git for around 100dlrs online and git rid of that stuck 30 lbs pos of a cat its proply almost plugged anyway. I ran flowtech afterburners on my 78 imp 4dr when i was daily driving it also had 2 flowmaster 40 series mufflers with a 2.5 pipe kit from jegs that 3exit outside front of the tires it was like 120 for pipes 75 each muffler and 150 for headers o btw the headers from a g body same year work just fine.
 
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