C3 headers

SRountree

Well-known member
Joined
Apr 12, 2015
Messages
352
Location
Cincinnati - Middletown OH
I have a 383 stroker and I wanted to run 3" pipes all the way back. Any suggestions or things to look for?

How do I know what size header to buy? I see different primary tube sizes. im also thinking about the Borla Atak muffler. Any thoughts?
 
I have a 383 stroker and I wanted to run 3" pipes all the way back. Any suggestions or things to look for?

How do I know what size header to buy? I see different primary tube sizes. im also thinking about the Borla Atak muffler. Any thoughts?

1-3/4 primary I think is pretty standard for an off the shelf long tube header and is likely more than adequate for a 383. Someone else who knows more about engine building than me could probably confirm this if you gave your cylinder head and cam specs though. If I recall, there was an issue with some brand headers that were very close to, if not hit, the floor (might have been LS swap headers, I dont remember) so just do some fitment research before you buy.
 
I have Speedway shorty headers dumping into an adapter to run into much larger pipes. It doesn't seem to impact flow much at all.
 
Most headers available for a C3 are the usual suspects, Hooker etc. because of clearance issues with the steering box, clutch linkage etc. I ended up adapting Chevelle headers but I have a R&P and hydraulic clutch. Still required modifying the headers.
 
Guys thanks for the comments. If i understand, i need to look for the 1.75" tube running to a 3" collector but I need to be aware of clearance issues. does that sound about right?

Silly question, are the ports on the heads different sizes too? Or does it matter as long as i use the 1.75 tube?

I was told my 383 should be running about 630 HP. I am getting ready to install the flaming river R&P so the headers shouldn't be an issue with clearance. I also elimated my clutch linkage with a hydraulic clutch system.
 
Chris, how can I find out what my cylinder heads are? Compression ratio?

I installed an edelbrock low profile manifold with two 4bb carbs, matching cam to make the set but i have no idea on the cylinder heads or compression. I want to say the guy told me it was a 11 to 1... the invoice ink is a little tough to read.
 
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Chris, how can I find out what my cylinder heads are? Compression ratio?

I installed an edelbrock low profile manifold with two 4bb carbs, matching cam to make the set but i have no idea on the cylinder heads or compression. I want to say the guy told me it was a 11 to 1... the invoice ink is a little tough to read.

Do you have the cam specs? The cylinder heads should have a part number stamped on the face that would give you a clue...

a 630hp naturally aspirated 383 is going to be a pretty rowdy motor. Most of the big cc runner heads have raised exhaust ports which could hurt you with floor fitment. But in terms of tube size, we have a ~600hp 406 with 1.75" primaries in our shop car (not a vette) and it seems to do OK.
 
my cam spects
ERSON CAM E110118

Duration @ .050: 236/244
Duration Advertised: 302/310
Grind Number: HL-302-355-1
Gross Lift: .532/.532
Gross Lift 1.5: .532/.532
Gross Lift 1.6: .568/.568
Lobe Center: 112

I dont see any casting numbers on the head unless my bracket is covering it. The numbers on top are 1 007 CF GT7 R1. not sure if that helps. my rockers are 7/16 1.6...
 
my cam spects
ERSON CAM E110118

Duration @ .050: 236/244
Duration Advertised: 302/310
Grind Number: HL-302-355-1
Gross Lift: .532/.532
Gross Lift 1.5: .532/.532
Gross Lift 1.6: .568/.568
Lobe Center: 112

I dont see any casting numbers on the head unless my bracket is covering it. The numbers on top are 1 007 CF GT7 R1. not sure if that helps. my rockers are 7/16 1.6...

With that cam and my not-so-professional opinion I would have to imagine a 1.75 primary would do you just fine...
I think ARH did some development on a member from CF 's C3 convertible for proper fitment. I think his name was gordonM if you want to search threads over there... They sure do look $$nice$$

https://americanracingheaders.com/collections/corvette/products/c3-corvette-1968-1982-long-system
 
I did some looking around and those Headers are priced decent for what you get. im pretty set on them now. I'm thinking about the Borla XTAK mufflers.
 
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I installed the 2.25 you mentioned on the car but I deffently want the 3" so my motor will breath a little better. I wish they had the 3" set...

They used 2.25 on the big block cars, so they can't be too bad. I almost didn't post the link, but they are really a good deal. After removing them, I put them on a for sale ad and they sold quick.
 
Yes they are stainless but the colector has a 2.5" reducer and I need 3inch. I responded to them to see if they will send them to me but for what I paid, I can buy different collectors.

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I installed the drivers side and everything was smooth. I actually have more room for the rack n pinion. Passenger side goes in tomorrow. So far I think I did good on the cheap headers.
Before

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After
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]
 
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Looks like a good fit. You planning on some "Heat Socks" on the ignition wires? Look like they could get warm.

Nice choice - BTW - you'd be hard pressed to DIY headers at that price.

Cheers - Jim
 
Great thinking Jim. Question, do the socks work good? I was planning on buying the high temp wires from Summit racing and get the socks too...

I got the passenger side done tonight and it fits great. I need to work on getting the heater hoses and the fan wire harness done so I can get it to the shop for an alignment. The exhaust will come after that. I'm getting closer.

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