Exhaust header frustration

[klkordzi]

I have a 2006 Ultra with a California Sidecar trike kit installed. I recently changed the clutch and had to remove the rear header to get the primary case off. Everything went smoothly until I tried to reinstall the header. I have tried everything to get this header to seal. The rear header crosses over to the left side and then back to the rear of the trike. I have tried installing the header pipe without the tail pipe attached and with the tailpipe installed loosely. The header where it goes into the head is squared off, not tapered and I have tried OEM tapered gasket and SE flat gaskets but neither seems to make a difference and I end up with a significant leak where the header pipe goes into the head. Does anyone have a suggestion?

 

[klkordzi]

I actually haven't been. Would you suggest tightening the header pipe with or without the tailpipe attached?