I have a 440 stroker w/ TFS 235 and a fats 90/90 in my 2004 zo6.

Currently it is making 550/520 through lg 1 3/4 headers and stock tis.

I am going to intsll electric cutouts, but I want to know what diameter header I should get. (2 or 1 7/8)? Also, what brand?

Thanks in advance and I know I may get a lot of differing opinions.

 

if you are staying NA I would go with the ARH 1 7/8's

If you plan on spraying or supercharger then I would go the the ARH 2 or kooks 2's.

 

Kooks

 

For most power, the bigger the better. For drivability keep it to 1-7/8"s.

 

1 7/8"stepped to 2", middle of the road.

I've got 1 7/8" on my 427ci and they're great, go with the 1 7/8" stepped to 2". You're making alot more power than me and can use it.


.

 

Hell I run 1 7/8 stepped to 2" on my little ol' 404. I didn't notice ANY drivability loss from my old pacesetters. Someone please educate me on how a 2" header could hurt drivability...

 

I would go with 2" regardless of your setup (NA, FI). Driveability will only be affected in the sense that you will lose low end, but you will gain up top. With that displacement youll have more than enough low end to even tell the difference anyway. What are your cam specs?

 

I think with 440CI/s there will be NO low end power loss. I bet that thing makes 450ft/lbs by 2k RPMS haha

 

I bet more than the headers your 90/90 is going to hold you back a lot. I would go for 1 7/8" stepped to 2" or just straight 2".

 

1 7/8 if its a street car.

 

Well said, err typed!!!

Being a kooks guy I'll add to that vote!

 

1-7/8's unless you're looking to be over 800 to the tire no need for 2". At your current HP level I bet the 1-3/4 are'nt hurting you enough to warrent changing them. If you want call the shop and speak to Nick and go over your combo with him and any more mods you plan like forced induction and we'll point you in the right direction.

 

Thanks to all and I will give AHR a ring.

As for differences between Kooks and AHR, do both have merge collectors? (My tuner here in Texas is a Kooks dealer so obviously he wants to sell me Kooks). I just need to know advantages/disadvantages of each and if differences are significant.