Topic: Exhaust Opinion Needed
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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Well I started the 72 today and all is good. Now for the break in I used the stack manifolds, but they will be coming off in the next day or too, and a new set of ceramic headers will be going on. Now the question is should I go with a 2 1/2" exhaust system or a 2 1/4 system. I have new flowmaster 40 series mufflers that are 2 1/2" in/out. I can use them either way as the system will be custom bent. The engine is a 383 stroker bored .040 with a .480/.490 lift hydraulic cam.
trans is a 2004r with a 3000 stall converter. I'm thinking stay with the the original thought of a 2 1/2" system but was wondering what others thought. I already replaced the original trans cross member so that wont be an issue.
Rodney
trans is a 2004r with a 3000 stall converter. I'm thinking stay with the the original thought of a 2 1/2" system but was wondering what others thought. I already replaced the original trans cross member so that wont be an issue.
Rodney
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I would go with the 2.5 inch, Rod. You'll need all the flow you can with the setup you have! That's what the later models used, anyway! Get busy! Hope your Dad is doing OK.
Barry
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Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
I agree...let that baby breathe!
Lifetime MemberHOWELL, NJ - USA
Joined: 5/18/2004
Posts: 6812
Vette(s): 1979, Targa Blue (72 Color), Pace Car rear spoiler, L88 hood, Dark blue factory interior, 525HP 406, HD 700R4, 370 gears,Steeroids, composite rear spring, TT IIs wrapped in T/A Radials.
Definitely 2 1/2" 
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2.5 all the way..................
corvette440hp
More flow is always better. I went with 2.5 true dual on my 79 with L48 and only mild performance upgrades. It made a nice difference over the stock 2" into 2.5
C3: 1979 Corvette Coupe, Auto, L-48, Red/Doeskin (my wife's fave);
C4s: 1986 C4 coupe (SCCA road race car), satin black, 4+3, Z51 package, L-98; & 1993 C4 coupe, white, 6-speed, LT-1.
When "The Toy" needed pipes a few years ago I went with the 2 1/2". Kept the original exhaust manifolds though - which are 2". Crazy part was the mufflers were 2 1/2 going in and 2" coming out. They didn't make 2 1/2" bezels back then.
Jim Olson 
"The Toys"...!!! Save the Wave! 
Boy am I late on this one.
Anyway. I installed a Magnaflow system on my 73. It comes out of the stock manifolds at 2 1/4" and enters a X-pipe which increases the pipes to 2 1/2" all the way through to the mufflers and out the back staying at 2 1/2".
The system is Stainless all the way.
I did have to modify the mufflers outlet to except a tip out the back of my car to match the original setup. I then purchased tips with the 2 1/2" pipes.
Brian - NCM Lifetime Member
73 coupe L48, Flat-top pistons, Performer RPM Heads, Crane Cam and roller rockers, Holley 650 vac sec. Performer intake,
3.55 gear BTO 200-4R trans,
Leather seats, Seatbelt Plus 3point seatbelts, Pioneer CD player
Magnaflow Exhuast System
Dewitt radiator and dual electric fans
Borgeson Steering box
in Forum: C3 Fuel, Emission Control, and Exhaust Systems
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