well i just got back from force fed performance(local speed shop) and kieth the owner said he has installed 2 of this kinda of header(he thinks, did not say if it was a ls1 or lt1) and each time it was nothing but problems with leaking. i was curious if maybe this was an old version or if that he has his brands mixed up or is it true?

 

You can tell if its the old version if the weld is in the inside of the primary or outside of it where it conects to the flange for the head.

Just look at where the primarys run into the header flange, like around where the bolts are, if you see a bead of weld then its the newer style. If you dont see the weld bead, then its welded on the inside of the tube to the flange and then ground down so it doesnt impede flow.

The case of my headers it was ground down to far and it caused them to leak. So i took them off and went to Pacesetter and exchanged them for the newer style.