Performance assistance
Thread Starter
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Joined: Oct 2015
Posts: 73
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From: NY
Performance assistance
Just looking for a little advice. I have a stock 1976 with the only upgrades being a performer intake and performer 4bbl carb. I wanted to add headers, but can't figure out which ones will fit correctly. I have new magnaflow mufflers on the stock exhaust from the manifold back. My question is, is there any performance value in just replacing the old exhaust system with true duals from the stock ram horns back to the magnaflow mufflers? Thanks in advance for any advice.
Burning Brakes
Joined: Oct 2012
Posts: 1,152
Likes: 252
yes.
Also, there are an uncountable number of threads on the advantages/dis-advanted of true duals vs X pipe vs H pipes so read up.
Last edited by Dynra Rockets; Aug 13, 2017 at 03:00 PM.
Thread Starter
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Joined: Oct 2015
Posts: 73
Likes: 2
From: NY
Thanks for the response. Actually, I spent countless hours reading through post to get information on headers, but could not find a definitive answer on what fits correctly. I have also researched the duals with the same results. I understand everyone has their preference and I was just looking to hopefully get a definitive answer, as I'm a novice when it comes to mechanics and this is my first Corvette that I'm trying to turn into a thing of beauty. I have really learned a lot from various members on this forum. Thanks to everyone for all the assistance.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
I must advise you that the 'performance increases' obtained by the Performer intake and carb amount to a net improvement over the stock equipment of about ZERO. Sorry.
You can net some improvement with headers; but because of the limitations of the stock heads and inability to flow well, gains with the headers won't be that much, either. [maybe 25 hp]
Heads, cam, headers, recurving the distributor for performance and making sure the ignition is in good shape will get you the boost you are after. If you're not up to that much change, stay with the distributor re-curve and headers (if you want). But, that won't throw your head back in your seat. Best just enjoy what you have until you do the major overhaul.
You can net some improvement with headers; but because of the limitations of the stock heads and inability to flow well, gains with the headers won't be that much, either. [maybe 25 hp]
Heads, cam, headers, recurving the distributor for performance and making sure the ignition is in good shape will get you the boost you are after. If you're not up to that much change, stay with the distributor re-curve and headers (if you want). But, that won't throw your head back in your seat. Best just enjoy what you have until you do the major overhaul.
Le Mans Master
Joined: Oct 2005
Posts: 6,247
Likes: 471
From: Glen Allen, VA
I second the idea of a distributor recurve. Research that here and give it a shot. I think you'll be very surprised how it makes your engine perk up. Best of all, a set of replacement springs and weighs for the distributor is about $10, in a Mr Gasket distributor recurve kit. I had never done this before learning about it here, and once I did it (it was very easy) it really woke mine up.
Burning Brakes
Joined: Mar 2013
Posts: 750
Likes: 180
From: Springfield Missouri
One of the first things I did when I bought my 76 in 2013 was to replace the stock exhaust with true duals. IIRC, the kit was for a 73/74 from Corvette Central and it clamped together. It didn't turn it into a race car as that's not what I'm after, but it did improve performance and more so after I rebuilt the Q-jet and replaced the stock cast iron intake with an OEM aluminum one.
Thread Starter
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Joined: Oct 2015
Posts: 73
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From: NY
Thank you all for the information. I had never heard of this distributor recurve kit. I will definitely look into this. Is this hard to do? I'm not looking for a race car either. Just want to improve the performance and sound. I will look into the true duals from Corvette Central. Did this system bolt right on to the stock ram horns, or do you have headers? Thanks again for the info.
Burning Brakes
Joined: Mar 2013
Posts: 750
Likes: 180
From: Springfield Missouri
It bolts to the ram horns. Be prepared to pull the ram horns if one of the bolts break. It's not a big problem unless you have an AC car as the AC bracket is a PITA. If you go this route try to maintain clearance between the exhaust pipe and the starter as mine is so close I wrapped the pipe and the starter to solve a heat soak problem with the starter. It might not be a bad idea to pull the starter and go through it so you won't have to do it later. Take the starter apart and clean everything and don't lose or misplace any shims and if the brushes show a lot of wear, replace them. I would probably just replace the solenoid as, IMHO, it's the weakest link in the starting circuit.
Good luck and PM me if you have any questions.
Good luck and PM me if you have any questions.
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Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
Re-curving the distributor is not difficult. It is essentially FREE power; setting the timing as is recommended by GM (at idle) is good for THEM but yields weak performance for your engine.
You need a decent timing light, a 9/16" open-end or box wrench; and you need to DOWNLOAD AND READ the paper on how to do this properly by Lars Grimsrud. Make sure you understand the process before you begin. If you have questions, ask here FIRST.
As far as making the C3 "sound" better, dual exhausts will help if you have a single-exhaust system. If you already have dual exhausts, changing the mufflers to a mellow sounding Magnaflow type will do that job for you. If you are not reworking the engine, keep the stock headers (more trouble than it's worth to change them for headers), but install the duals with Mangaflow mufflers.
You need a decent timing light, a 9/16" open-end or box wrench; and you need to DOWNLOAD AND READ the paper on how to do this properly by Lars Grimsrud. Make sure you understand the process before you begin. If you have questions, ask here FIRST.
As far as making the C3 "sound" better, dual exhausts will help if you have a single-exhaust system. If you already have dual exhausts, changing the mufflers to a mellow sounding Magnaflow type will do that job for you. If you are not reworking the engine, keep the stock headers (more trouble than it's worth to change them for headers), but install the duals with Mangaflow mufflers.
Last edited by 7T1vette; Aug 14, 2017 at 11:26 AM.
Instructor
Joined: Jun 2017
Posts: 214
Likes: 22
From: Satellite Beach Fl
I just did the exhuast and it was simple. I did it by myself in the garage with 4 jack stands and a floor jack (as my helper to hold the pipes in place while I tightened things up. MUCH BETTER. I have the re-curve kit sitting in front of me and will be doing it as soon as I finish up the suspension maintenance.
Instructor
Joined: Jun 2017
Posts: 214
Likes: 22
From: Satellite Beach Fl
Is your car an auto or 4 speed? The reason I'm asking is if it's an auto you will need a custom bracket from Allen's exhaust. I might have an extra laying around that you can get from me a little cheaper. It's new, but it did come pre-scratched from Mid America...
Last edited by jlpskydive; Aug 14, 2017 at 04:24 PM.