2.5" N11 system on a C3
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,303
Likes: 36
From: Allen Park Mi
2.5" N11 system on a C3
I'm looking to run a 2.5" system with N11 mufflers on a 1971.
Car currently is a 350/270hp 4speed - but i'm gonna rebuild the motor as a 1970 spec 11:1 LT1
planning to run 65 L76 exhaust manifolds which have the 2.5" outlet.
I was told that the C2 and C3 exhaust is different, yet the frame is the same - not quite sure what or why the the exhaust would be different other than the rectangle tips (which I would plan to use)
Any advice here?
Car currently is a 350/270hp 4speed - but i'm gonna rebuild the motor as a 1970 spec 11:1 LT1
planning to run 65 L76 exhaust manifolds which have the 2.5" outlet.
I was told that the C2 and C3 exhaust is different, yet the frame is the same - not quite sure what or why the the exhaust would be different other than the rectangle tips (which I would plan to use)
Any advice here?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Most L-48 blocks have 2-bolt mains; LT-1 blocks are 4-bolt mains. You can build an L-48 block with LT-1 parts, but if you rev the engine to 6500+ rpms, I'm not sure it will hold together.
Other 'real' engine builders might want to weigh in on this.
Other 'real' engine builders might want to weigh in on this.
Melting Slicks
Joined: Jul 2004
Posts: 2,131
Likes: 102
From: Toms River New Jersey
I'm looking to run a 2.5" system with N11 mufflers on a 1971.
Car currently is a 350/270hp 4speed - but i'm gonna rebuild the motor as a 1970 spec 11:1 LT1
planning to run 65 L76 exhaust manifolds which have the 2.5" outlet.
I was told that the C2 and C3 exhaust is different, yet the frame is the same - not quite sure what or why the the exhaust would be different other than the rectangle tips (which I would plan to use)
Any advice here?
Car currently is a 350/270hp 4speed - but i'm gonna rebuild the motor as a 1970 spec 11:1 LT1
planning to run 65 L76 exhaust manifolds which have the 2.5" outlet.
I was told that the C2 and C3 exhaust is different, yet the frame is the same - not quite sure what or why the the exhaust would be different other than the rectangle tips (which I would plan to use)
Any advice here?
Last edited by SIXTYTWO; Jun 10, 2018 at 04:40 PM.
Drifting
Joined: Mar 2009
Posts: 1,461
Likes: 361
From: Monson MA
Exhaust
I've been restoring a 68 and used Hooker Competition headers paint. I bought CC 2 1/2" intermediate pipes and N11 mufflers. I had the intermediate extentions to connect to the headers made at a local mffler shop for $150.00. I had the whole system ceramic coated inside and out. The whole system installed pretty routine. Fit the frame and factory hangers.
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,303
Likes: 36
From: Allen Park Mi
cool thanks all.
I"m gonna go with the Gardner LT1 system which they'll build with 2.5" headpipes, then I can use 65 L76 manifolds - and that should help it breath a little better than the 2" manifold
Cheers
I"m gonna go with the Gardner LT1 system which they'll build with 2.5" headpipes, then I can use 65 L76 manifolds - and that should help it breath a little better than the 2" manifold
Cheers
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
