[AWeb80]

my question is what size primaries should I use and where should I place a secondary collector....or should I dump all six primaries into the DP area?

...any and all input you have on this, please come forth....EX: specs, material to use, size, layout....ETC.

why is it "customary" to see the primaries as close to equal length as possible? I think I know the answer, but want to see what you guys say.

does anyone have any pics of theirs?


here's my current engine bay.....not too much room...but I'll have all winter to figure it out since the GP is not my DD.

[AWeb80]

oh, and what size should the flanges be? Thickness wize?

I have no problem getting them made....we have reverse engineering and laser cutting machines where I work.

[AWeb80]

I am thinking about copying this design...





-do I need a flex bellow similar to the stock manifolds?
-Or will I be ok running a sraight pipe?
-Does anyone made a 3 pipe collector for headers?....all I can find are 4 pipe collectors




or should I just go the "power log" way of the 3800's?

[3400-95-Modified]

You should always have a piece of flex after a header, not necessarily in between the front bank and the rear, but you need something after it so if and when the motor does move it wont make your whole exhaust move and hit stuff.

And why build your own when SS ones fit your car... Seems easier to buy their design rather than attempt to copy it.

[AWeb80]

I didn't think they did fit. i thought the rear header didn't fit right. besides, i love making my own stuff. and this is something i can do over the winter. and for way cheaper.

[montess408]

hey who made the "power logs" for the 3800 ? they are nice a set like that would be a big improvment over stock manies for sure not as good a real headers but alot eazyer and less expencif to make !

[3400-95-Modified]

didn't the 3500 GP swap kid on here use SS headers without modifying them? IIRC he did.

[bszopi]

http://60degreev6.com/content/Headers

Primary size ideally would be either 1.5" or 1.625". Ideal primary length for these engines is around 31-33", although I doubt you'll want to try to fit that in your bay. As far as the flange goes, I would say min thickness of 3/8". And I did the CAD work for the flanges that Geoff (betterthanyou) sells, so I would be willing to send you the file so you can just plug it in and cut away.

[AWeb80]

Originally Posted by 3400-95-Modified

didn't the 3500 GP swap kid on here use SS headers without modifying them? IIRC he did.

Yes, but IIRC he had a hard time w/ the rear and had to modify it quite a bit to fit past the firewall.

He said the fronts fit great though. I'm not going to spend $700 on headers when I can do them for way less.....I built my 2.5" DP for $25 in materials. A local shop wanted $300 to start.

[AWeb80]

What wall thickness should I aim for?

and where can I find a 3 into 1 collector? I've looked all over.