I would like to know what everyone is doing for headers and a mid-pipe on these years. The car is a auto, with ac. I found some Sanderson headers that will work on the car I think. There are 4 different ones just need to figure out the correct one that I like and will fit. I also wanted to take the converters off. The car is being registered here in Texas as an antique car so not emissions. Any input. Do you need to run MIL`s? To not have a tuning issue with the converters? Does anyone make a kit for the mid-pipe that is true duels or just a y pipe? Is there anything else I need to know. We are removing the Engine and Tranny next weekend to start to freshen up the engine back and front suspension on the car. Thanks for your help

 

Taking out that ancient cat really wakes up the engine. mine ran incredibly lean once it was out. I'm debating what to do with my engine so for now I got the cheap Patriot sidepipes and ran some flex pipe to them. I believe you can get a true duals kit from Mid-America; there may be other vendors but I think that was one I looked at over a year ago. The Patriots killed half the HP I gained without the converter at least. Thought this info may be valuable to others. I have a set of hooker long tubes and a set of coated block huggers waiting on my engine decision. I hear the block huggers can melt the engine mounts so I haven't decided which to install yet myself. In the long run I think long tubes are always the best way to go.

Not sure what MIL's are?

 

I have a 77 with auto. I bought 2.5 inch duals, aluminized pipes, from Mid-America. They fit alright although many people here will say you should have a muffler shop fab your pipes. I have Dynomax ceramic coated headers, from Jegs. Use small primaries, 1 5/8 inch. I did have a muffler shop modify the front pipes to match the header collector location. I'm using Magnaflow mufflers - not too loud. Another thing you will need is the pipe support at the crossmember to hang the second pipe where it passes thru the trans crossmember, otherwise it will rattle. Mid-America sells those too. No cats on my car either.

 

I installed the 2.5" true dual kit from Corvette Central. Bolted right up to the stock exhaust manifolds on my 76 with no problems. Came with Magnaflow mufflers. I stayed with the stock exhaust manifolds because all the research I did showed that GM's manifolds do a pretty good job, and the HP gain with headers was not all that much. Now, if you are going to race your car and need the few extra HP that's different. You will definitely notice a difference when you get rid of that "Y" pipe and the cat and go with the duals.

 

I also have true duels from c.c. they make Quite a difference. I had Flo-tech headers with 2.5 pipes but didn't like the way the collectors were welded to the the second pipe.Too close to underside.I like just the 2.5s connected to the stock manifolds.Sounds nice.I think you need the kit for a 74.Have fun!

 

I am tossing the 2 1/4" factory system off of mine. I bought the Hedman Ceramic coated headers and the Pypes stainless dual system from Summit. Just going to true duals will make a difference.

 

I ditched all emission stuff, dropped a ZZ3 crate ( this is an automatic car), aluminized exhaust from Corvette Central 2.5" straight thru, no Y pipe, Headman ceramic coated headers, stock mufflers in rear. I did leave the exhaust assembly in sections, so that if needed I can take it apart and work on it easier. I took it to get inspected, and they were so "WOWING" about the car they didn't pay any attention to and emission items.

Hope this helps!

 

I've got a 79 and just replaced my stock setup with pre-79 (I think they were specified for 74) 2.5 stainless true duals and Dynomax Ultra-Flow mufflers from Ecklers. I'm still using the stock exhaust manifolds. As BKBroiler mentioned, you may also need to modify, or replace the pipe support at the crossmember. In my case, we modified one a buddy of mine had laying around the shop to work.

I love the performance increase and improved sound with the duals and new mufflers, but I'd reccomend at least checking a good local exhaust shop to fab your pipes because, in hindsight, the fitment from Ecklers on the pipes themselves SUCKED. We had to weld in an extra section on the left pipe to make it match up with the right at the back of the car and probably would have been better off sending them back and getting some fabbed up. It's done now, but I can still see a few imperfections related to fitment which gets to me because I'm too much of a perfectionist!

I'm in Texas too and my car is registered as Classic. I had it inspected right after getting the exhaust replaced without issue, but they didn't even look under the car at the place I had it inspected. I think 25+ years in Texas excludes you from any of the emissions tests, though a more detailed inpector might be able to technically nail you for not having cats. Not sure on that as far as the various years of Vettes go.