How do I choose headers?

So, I've got a '77 C10 Scottsdale. I have a SBC 400 (406) engine. It has aftermarket aluminum heads with square port exhaust.
I haven't lowered the truck, and don't plan on it. It's actually pretty low right now.

How do I choose performance headers?

Thanks

Go to Summitracing.com and use the filter

Do like i did, pick up whatever you got layin around and try it, if they work go with it! Lol jk thats not a good way but thats how i did it lol

How zoomy is your 406?
The way that was built will play into what works well and what sucks ass.
We need more info like cam, compression, intended use?

A slow moving trail truck will require something different than a hot street brawler.

You will probably want to start with a 1-5/8 to 1-3/4 inch primary size tube.
Then most will have a 3 inch collector on them.
That is easy to step down to 2-1/2 inch or keep at 3 inch.
Just depends on what is under the truck now or what you plan on putting under there.

Catbox said:

How zoomy is your 406?
The way that was built will play into what works well and what sucks ass.
We need more info like cam, compression, intended use?

A slow moving trail truck will require something different than a hot street brawler.

You will probably want to start with a 1-5/8 to 1-3/4 inch primary size tube.
Then most will have a 3 inch collector on them.
That is easy to step down to 2-1/2 inch or keep at 3 inch.
Just depends on what is under the truck now or what you plan on putting under there.

Click to expand...

It should have some pep... we'll see.

IIRC, my pistons are L2467 flat top with valve reliefs.
Comp 12-423-8 Roller Cam
Weiand 8004 Intake
Quick Fuel SS-735-VS Carb

Aluminum Heads- 200cc, 64cc,
2.02" Intake, 1.60" Exhaust,
1.6 roller rockers

Rich77 said:

It should have some pep... we'll see.

IIRC, my pistons are L2467 flat top with valve reliefs.
Comp 12-423-8 Roller Cam
Weiand 8004 Intake
Quick Fuel SS-735-VS Carb

Aluminum Heads- 200cc, 64cc,
2.02" Intake, 1.60" Exhaust,
1.6 roller rockers

Click to expand...

I would start with the 1-5/8 inch tubes if it were my engine build.
Unless you plan to step things up at a later date.
Then I might buy the 1-3/4 inch headers and just deal with the little bit of power loss until then.

To me your heads say street brawler with the 200cc intake ports.

Your cam and intake choice seem to be one step below that as they are from just above idle to 6000 rpms.
It should run like a champ, but there may be some left on the table, who knows...
One day down the road you may want to step up the intake to see how that effects your power output.

I am currently helping a teenage kid form a recipe for his own first engine build.
I have to keep telling him to find a recipe and stick to it.
One of his friends has no clue and keeps misleading him.
He was looking at some 200cc intake heads and we got him back to thinking the 185cc heads would be a better choice for him as he will be looking to keep the intake port velocity up.
However his is just a 355 and yours is a 406, so the added displacement will probably help keep the velocity up.

My motor is similar to yours, measured compression ratio was 9.6 to 1. Steel 194 Heads have three angle valve job, ports full ported. Weiand stealth, 4160-3310-3 750 cfm carb. Cam is a crower 234 at .05 (284) duration .520 lift, lumpier then I like. Cam installed straight up, full advance is 41 degrees, and will run on regular, but likes premium. Dyno Hp was 325, torque was 310. You will make more. 1 5/8 headers will give you more torque, but a 400 is a big block basically. I am switching to a 454, built in a similar fashion, except the heads are stock. Bought 1 3/4 headers. Headers are expensive, so better to go to 1 3/4 as I think 1 5/8 would suffer if you run the engine hard, (I tow) and I run the pooh out of all my rigs. She will burn the tires in 4 low hubs out.....just in case you want to....

Whatever you decide, I'd recommend ceramic if available and within your budget.

The heat generated by un-coated headers can lead to a myriad of problems.

I know, we all got along with un-coated headers for decades but over the years they led to cooked wiring and starter problems.

YMMV.

I used 72 Malibu/Monte Carlo Hooker headers, clearance everywhere EXCEPT you have to change or modify the cross member. They tuck up nice in the frame and give good clearance for lowered trucks.