Basic header tech questions

[Bowtieracing]

Since it seems impossible to find headers what i am looking for . I try to build them myself.

- Where can i get stainless flanges wich match for LS7 exhaust ports ?

Stainless works lists 1 5/8" and 1 3/4" models only. I want 1 7/8" primarys.

- I try make primary lenght close to kooks long tubes. Is there any gains to

use merge collectors with long tube desing ? See link :

http://www.stainlessworks.net/cart/p...oducts_id=1238


One more. 1 7/8" is outside diameter whan talking about primary tubes?

Thanks!!