1 7/8 inch headers

[kornball426]

Hey guys I was wondering if anyone could help me out. I'm searching for a set of 1 7/8 primary headers for a traditional SBC that will fit a G body, and here is the most important part, with the factory air conditioning box in place. I don't want to remove the HVAC or go to the expense of a vintage air system. Ideally I'd like stainless or ceramic coated for longevity, not to mention rusty headers look terrible, not that it's a showcar.

I don't really care if they're shorty, mid length, or long tube. I was just advised by the tech guys at Brodix that with the heads on my engine using smaller headers may choke it off a bit/flanges block the exhaust ports to a certain extent. They're CNC ported heads and the ports are huge if you put them next to a stock 906 vortec casting so I think they may be right.

 

[565bbchevy]

If you are concerned about restrictive headers I wouldn't do anything but a full length header.
What is your budget for these?

Chevy G-body Small Block 1978-1988 Headers

If your SB Chevy G-Body needs a set of top-notch headers that fit and perform great, your search is over. These headers will work with straight or angle plug heads, with or without AC and manual or automatic transmissions. Primary size up to 1-7/8" available. These headers have been prototyped...

americanracingheaders.com

SB Drag Race and Street Headers

 

[kornball426]

If you are concerned about restrictive headers I wouldn't do anything but a full length header.
What is your budget for these?

Chevy G-body Small Block 1978-1988 Headers

If your SB Chevy G-Body needs a set of top-notch headers that fit and perform great, your search is over. These headers will work with straight or angle plug heads, with or without AC and manual or automatic transmissions. Primary size up to 1-7/8" available. These headers have been prototyped...

americanracingheaders.com

SB Drag Race and Street Headers

It may have been a stupid question, I'm a little overwhelmed by all the different choices.

I'm not sure how big the difference in the actual port size on the headers is between brands and primary tube sizes, I never had a problem with basic cheap off the shelf headers on my other cars.

however the thing that's got me concerned with this engine is they're large D shaped (large LT4, Brodix recommend FelPro 1406 gaskets) exhaust ports, and the vast majority of headers seem to be 1 5/8 oval or round port. I'm worried using a smaller wrong shaped port header flange is going to literally be blocking off part of the port as it's the wrong shape and meant for a basically OEM size port, as opposed to a large D port. I'm also worried even if the oval port headers don't block the port, they're not going to seal. Although that's probably an unfounded fear since the heads are one smooth machined surface on the exhaust side.

I'd like to keep them under a thousand, 800 or less would be great, it's not that I can't spend more, but this is not a race car or show car by any means so extracting every last horsepower is not a concern, I just don't want to cause any unjustified restriction in the exhaust by having the wrong headers, and I need them to seal. And I need them to fit witthout removing HVAC which is a primary concern as well.

 

[565bbchevy]

For your price range in a 1-7/8" header for a Gen 1 SBC you will probably be limited to a coated steel header, all of the affordable stainless headers are for LS swaps in our cars.

 

[kornball426]

For your price range in a 1-7/8" header for a Gen 1 SBC you will probably be limited to a coated steel header, all of the affordable stainless headers are for LS swaps in our cars.

I'm fine with that, I just don't want paint... I've dealt with painted headers exclusively before on my previous cars and it sucks compared to guys with ceramic or stainless.

Fitment is the big issue shoenfeld for example specifically says their 1 7/8 G body headers won't fit with factory AC the only other option I really see on Summit/Jegs in that size is Hooker super comps but they make no comment on them fitting with the AC box in place (I sorta doubt it), I don't want to buy an almost thousand dollar set of headers and then not have them fit.

I do see a set of 1 3/4 ceramic ones that are actually for a D port from Dougs headers for like $700 which may be the way to go if I can get in contact with them and see if they can tell me if the gasket they recommend is the same dimensions as Brodix recommend. The slight step down in primary diameter would probably be beneficial for my goals IF there's no prob with the port being too small. Slightly smaller tube should theoretically be more low end and mid range friendly, and easier to fit in the car.

 

[pagrunt]

What about Thornton stainless shorties dispite being 1-5/8". They do have more of a OE type square port to match the heads which should help with possible choking at the port, supose to fit very simular to stock older manifolds.

Thornton SBC Headers - Classic Muscle Car Exhaust

New Thornton shorty header design for Small Block Chevys. Thornton style headers are designed for easy fit without the hassle of exhaust leaks. These headers were designed from 1969 Camaro cast iron GM manifolds 3942529 and 3932376 and are a stock replacement for factory manifolds. They will A...

classicmusclecarexhaust.com

 

[Bitterman]

I'm running a set of flowtech tri Y full length headers. Mine are painted but I believe they have them in ceramic coated. Check them out.

Fitment on my 1980 cutlass with a 350 SBC is great. No hitting or rubbing anywhere. I am also running full AC system on my car. No issues.

I have only run my headers during engine break in. No true life road test results yet.

 

[bracketchev1221]

What heads are they? I’m thinking with ac restriction I would be looking at 1 3/4 headers and calling it a day. A good 1 7/8 header on a small block port doesn’t fit without adapter plates. So to use a 1 7/8 without the plates is still a restriction.

 

[Bitterman]

Heads are regular cast iron heads. I think the flowtech headers are 1 3/4 inch not the 1 7/8 you were looking for.

 

[kornball426]

What heads are they? I’m thinking with ac restriction I would be looking at 1 3/4 headers and calling it a day. A good 1 7/8 header on a small block port doesn’t fit without adapter plates. So to use a 1 7/8 without the plates is still a restriction.

Brodix IK210's CNC ported 210cc intakes same as these ones here, but mine should have springs for a solid flat tappet not solid roller. They claim to be able to use standard bolt pattern headers (no mention of adapters, yet Brodix customer support told me the best headers to use for my combo is 1 7/8) https://www.jegs.com/i/Brodix/158/1028107/10002/-1