The 2nd one.  To really pair cylinders for any kind of benefit you have to cross over between banks.  The tri-Ys do avoid some of the big midrange torque dead spot that long tubes always have, but honestly shorties are a better setup for the street, and easier to package/install. 

I think I may have figured it out.
Following the firing order:

15426378
Or
13726548

no adjacent firing cylinder exhaust pulse hits the first “y” (same or consecutively)

I remember looking at this many years ago and figured out why the driver’s side was done differently.
I had to dig them out so I could see it.
Hey I slept since then.😁

This came about because I was looking at the original intake.
Was wondering which intake ports were paired together on a dual plane intake.
I figured that out as well.

Thanks

Yeah, my wife laughs at what I think about sometimes.😂

Last edited by Nos681 (6/20/2020 8:54 PM)

6sally6 wrote:

Study these!!!!!......

And here are some links -
https://www.summitracing.com/search/brand/dougs-headers
https://pertronixbrands.com/pages/the-original-dougs-headers
 

Those FPA look way better than the Doug’s in that advertisement.

From what I can figure, the H-pipe performed the same task by combining each bank together.
In a simpler manner.

Now here’s something I noticed...oh boy...
The Coyote engine uses a different firing order, but crank appears to still follow same pattern.

1-5-4-8-6-3-7-2

So...are coyote tri-y’s set up same way?

Last edited by Nos681 (6/22/2020 12:56 PM)

The H-pipe does serve a similar function in combining pulses, but the location of that merger is also important.  I'm sure it makes not a lick of difference on a typical street engine, but in racing they spend considerable effort to tune the lengths of the primary pipes, crossover point, etc.