1 3/4" or 1 7/8" SBC headers for 68 b-body?

[RaysnCayne]

Hey all,

Long-time fan, first-time poster here.

I'm not there yet with my 400, but a friend of mine with a 1968 Impala is building a 421" SBC (Gen 1). It's gonna have some beans so he wants to upgrade his 1 5/8" headers to something larger. Thing is, after some poking around at all the usual speed shops, there doesn't seem to be any off-the-shelf "big" headers for an SBC in an old b-body. Can anyone point me to a vendor/manufacturer that carries such an animal?

[TC]

Type of heads, valve sizes, compression ratio, and cam specs would be good to know......

[RaysnCayne]

I'm not really asking for input on header size based on a combo. I just want to know who makes/sells big SBC headers for an old B-body.

But for the record, he'll be using big AFR 235 heads, a fairly big roller cam. I don't know much about the 235s, but I'm assuming the exhaust ports are in a normal Gen 1 SBC location/configuration.

[Scott Liggett]

I went through the same issue. No mainstream company makes bigger headers for the car. I found Stahl Headers makes a stepped 1 3/4 to 1 7/8 headers but they wanted $1400 for them. Way out of my price range.

I wanted to try first gen Camaro headers thinking they are rear steer like the Impala, but they were $400 for an unpainted set from Hooker. I thought that was lot to pay for headers I may have to cut up.

I found a set of 1 3/4 headers at the swap meet for $50, but they were for big block mopar. Oops! So, I got rowdy and knocked off the mopar flanges, did some cutting and welding and added sbc header flanges. And voila! I had a custom set of 1 3/4 headers. I only spent a total of $160 total and a month of weekends building them. Check out my thread on the Impala to see what I did.

[anotheridiot]

http://www.speedwaymotors.com/Small-Block-Chevy-Header-Kit-1-7-8-Standard-Port-3-1-2-Collector,31670.html

http://www.speedwaymotors.com/Small-Block-Chevy-Header-Kit-1-3-4-Standard-Port-3-Collector,3843.html

http://www.sandersonheaders.com/Chevrolet-Small-Block-V8-Headers

First two if you can weld your own kit together, instead of hacking up a set. Sanderson is just a cool company that has patented flanges that need no pesky gaskets that would probably be a good place to ask if they can recommend something. Big tubes are gonna make spark plug changes pretty aggrivating, and pounding clearance in a set really sucks. Just think most headers are made 1.5 or 1.625 for a reason, which might make them enough.

[jcharliem]

I think it's gonna be tough finding that header size off the shelf for a b-body. A healthy 421ci could easily need the bigger pipes - yet, who would mass produce 'em for a b-body SBC?... I'm thinking few to no one. You may be in the realm of custom headers... yet, that's the price one pays when playing with stuff outside of the norm. Good luck.

[Scott Liggett]

I think it's gonna be tough finding that header size off the shelf for a b-body. A healthy 421ci could easily need the bigger pipes - yet, who would mass produce 'em for a b-body SBC?... I'm thinking few to no one. You may be in the realm of custom headers... yet, that's the price one pays when playing with stuff outside of the norm. Good luck.

They only make one size header for BBC's for that era of Impalas and its small.

[oj]

Give Kooks' a call down in N.C., they might be able to make a set. It is going to be expensive, that is a big motor and highflow head - i'd be looking at 2" tubes or 1 7/8 step to 2". Worst thing you can do is strangle that motor with small store-bought headers. It'll mess with everything from the carb and ignition to cooling the engine.