Sbc big tube headers for afr heads

[69restomod]

Hey guys wanting to see what you high hp standard Sbc guys are running for headers, just dropped off the motor to the engine builder for the new afr 210 cnc ported heads ported super victor intake and cam change on my 383 and the exhaust ports are about 1.60 x 1.5 square ports , and I have the Hedmann longtube headers with 1-3/4 primary's but the ports are 1.55 tall by 1.25 measuring side to side with the weld on the inside. And am thinking of tig welding around the outside and porting the inside dimension to match the heads or maybe buying new flanges and welding them on to the headers, or maybe there is a header out there that I don't know about that would fit my 69 c-10 any help would be appreciated!

[Marv D]

Unless I'm mistaken the 69 frame is the same as my 66 and all I can say is your looking at a set of custom headers to get anything bigger than 1-3/4" primary (AFAIK)
I'm pretty sure you already had to massage the passengers side frame rail to get what you have to clear right?

I'm currently running a set of AFR 220's ,,, and had a set of 1-7/8" headers built from a Headman Hustler package. My 220 heads are standard port flange and the headers for anything larger than 1-3/4" are Stahl pattern. Headman as well as Jere Stahl has a Stahl port adapter that bolts to the head, and you port it to the header . Be careful, the Stahl pattern is not a 'spread port' that's a different animal of head. Slummit and Jeggie carry the adapter but I didn't find it in a simple site search.

oh, here found a video on Stahl's site.
http://www.stahlheaders.com/af.htm

[69restomod]

Your exactly right Marc I had to massage the frame rail a little bit to get the 1-3/4 heddmann headers to fit, and my afr 210s are a standard port also, that helps a lot the port on the headers is plenty tall just not wide enough, I might try and port them and weld in them and see if I can get them to work, what Herman hustler headers did you have customized to fit your motor? I'm thinking if I can port might and make them work I'll run them for awhile the. Build a custom set cause the motor n/a should be around 600 hp and then a 150shot with a standalone fuel system with race gas, and 8000 Rpms its gonna need some good exhaust flow!

[Marv D]

Really it was just the flanges and stubs and a pile of piles and bends. the whole kit was a fab kit, not a completed set of headers.

[69restomod]

Ok cool do you have any pics of how they turned out? I've found some build your own kits with 1-7/8 primaries with 3.5 collectors that I'll probably end up using

[Marv D]

I use a front and mid plate instead of the side mounts so that gives more room for headers also


A closeup of the adapter flanges bolted to the heads



Sorry no picture I can find has better shot of them in the engine bay.

[69restomod]

Man those are an awesome piece very nice!

[69restomod]

[69restomod]

[69restomod]

Added these merge collectors that neck down to 3 then to a 3.5 outlet, gotta weld them up and then gonna mill the flanges to the opening of the gasket once my motor builder gets them to me and run them for now until I get some time to make a full set.

[Hollow65]

I'm on the hunt for some larger primary headers also. Seems like custom is the only option? Did you mimic a current design like hooker comps? Or did you just weld and mount and see what was working?

[nxtruck]

I had a set of custom headers built for my '66 several years ago by a guy named Tom Dawson. He used to work for Hooker Headers at that time and was able to use a set of 1 3/4" x 3" headers, jig them up, and build a set in 1 7/8" x 3 1/2" for me. They were built to use a pair of Hooker adapter flanges and fit very well on my AFR 227- headed 434. I believe he is still around, building headers out of his own shop.

[Hollow65]

Thanks, I'm gonna attempt some customs in the near future. You know I've left my ride alone for almost 12 years. I've been on this site for a week and sent my truck back to the shop this past Friday to get it all dialed in and freshened up. What have I gotten my self into? Hopefully I'll have some time slips in the coming months, or a cool obituary..

[moggey01]

Umm here goes. 2 -2 1/8-2 1/4 step with 4 inch collector. This was on a Pontiac headed 390 inch engine. Cast strip dominator manifold made to use a dominator carb. Heads were 227 c.c. intake port. Made a little over 800 hp.on motor in 1988 . Headers were made a little big because of nitrous.Was a real good combination.

[nxtruck]

Originally Posted by moggey01

Umm here goes. 2 -2 1/8-2 1/4 step with 4 inch collector. This was on a Pontiac headed 390 inch engine. Cast strip dominator manifold made to use a dominator carb. Heads were 227 c.c. intake port. Made a little over 800 hp.on motor in 1988 . Headers were made a little big because of nitrous.Was a real good combination.

That sounds like a very strong combo, especially if it was a nitrous combo running n/a. Were those Pontiac heads std. or raised port? Can you share any more info on this combo?

OP, sorry for the hijack.

[moggey01]

Yes it was a nitrous motor. Original std.port head. They seemed to be better than the raised ports. Jim Bell did the heads and manifold..Used a 2 stage plate 250 1rst kit,and 125 second.The manifold needs was welded up had runner extensions in the plenum. A sniper Jr. Would be close. You don't need compression with the nitrous. It made power to about 8000 rpm. The heads are the key. The intake ports were raised with epoxy around .200 I think. The engine was in a guy named John Jansky s 69 camaro we ran at Navasota a lot with 10.5 tires.

[nxtruck]

Very nice combo. The runner extension mod sounds like you could have ended up with something similar to a super victor, but in '88, the strip dominator was about as good as they came. Still a very good manifold. Do you know what block was used for this build? The aftermarket choices were slim in '88.

[moggey01]

Gm bowtie block. I used billet caps and had the rear main seal adapter. I know a guy that used a 400 block and a cast 400 crank (406)and made over 800 with iron heads. He hurt it pretty good with nitrous.