bubbaf100

What header designand size would be best for a SBC 421?

10.5 Compression AFR 235 heads,Demon 1050 carb, Edelbrock Fully Ported Super Victor, 675/645 278/284@50 106ICL 110 lobe sep. 4/7 firing order swap.
Need headers for drag use.

TheYellaBrick

What's it going in ?

zipper06

2" to 2 1/8" step headers with 4" collector, nothing smaller than 2" for sure.

JMO

Zip.

bubbaf100

Going into a 78 C10 Blazer.
No fenderwells. Build headers first then put fenderwells
back or actually cut them to fit.

cncmotorsports

Are your heads spread port exhaust?

bubbaf100

Yes it is a speadport exhaust.

cncmotorsports

1 7/8 to 2 inch, or just 1 7/8
You need more compression.

bubbaf100

I'm limited to 91 octane and a dish piston by rules.
I wish I could have more compression.
I have to run a 30'mile street test.
I have that taken care by a dual fan and dual radiator setup.

TheYellaBrick

what kind of event are you runnin', Anyway ? :shock: :shock:

bubbaf100

Ventura County Street Outlaw.
Up to 440ci displacement.
Limited to only smallblocks with 23 degree heads(On Chevy's)
Single Carb only unlimited induction.
Chevy's 23 degree heads Unlimited Modifications.
Limited to dish piston and 91 octane pump gas.
Unlimited transmission and unlimited rear end.
Unlimited Cooling.
Unlimited tire.
No power adders.
In the future I'll change classes and run 14:1 on Alky.
Dual 950 RS Demons with Hogan Sheetmetal intake.
Top it off with a Dual shot Fogger. 150 at the gate and another
200 shot. I'm crazy I'll still drive it then on the street too.