header pipe diameter for street use

[ChargerST]

What would be the preferred primary header pipe diameter for a 505ci engine? 95% street duty, 3.23 rear gears, 2.5" exhaust system. I don't want to pay for TTIs and I'm looking for options. I came up with Doug's and Hedman Elite headers.
Doug's are 2" primary 3.5" collector - Hedman Elite are 1 3/4" primary and 3" collector. Both are ceramic coated, thick flange, 14 gauge pipes.
Am I choking the engine with the Hedmans or are the Doug's too much for a street duty engine? I think 1 7/8" would be the best compromise but can't find much in this size besides TTI (I wish Doug's would be available in 1 7/8")...

Which header of the two would you take and why?

[c00nhunterjoe]

Depends on the compression and cam. Overall, in most apps on a 500+ inch build, the 2" tubes will be good, if it is a little more on the tame side, the 1 7/8 will give it more low end torque which may be better for your street use.

[firefighter3931]

If your choices are between the Dougs and Headmans....definitely go with the 2in primaries. The stroker will make a lot more torque than a traditional 440 so even if it loses 10 ftlbs at 2500 rpm you'll never feel it in the car. You would feel a 30-40hp loss with a header tube that is too small. 

It's all about trade-offs.....horsepower vs torque but the long arm stroker changes things. Get the 2in and don't look back 


Ron

[ChargerST]

Thanks! 
As I understand the higher torque numbers with smaller pipes are due to the backpressure (-> better cylinder filling). So in theory my small 2.5" exhaust would increase backpressure as well - maybe the large 2" will act the same as 1 7/8" headers.. 

[c00nhunterjoe]

If it were mine, i would run the 2" primaries into 3" exhaust with an x pipe and a straight through muffler such as the ultraflows or magnaflows.

[myk]

That's what I'm running and I couldn't be happier...

[firefighter3931]

If it were mine, i would run the 2" primaries into 3" exhaust with an x pipe and a straight through muffler such as the ultraflows or magnaflows.

Good advice ! You're in 3in exhaust territory with the 500in stroker....it needs to exhale efficiently for best results. 


Ron