Header Collector Connection

[Skipper]

I have recently purchased a MidStates Cobra and I'm having after-fire in the exhaust collectlr when shifting up. I've looked at the pipes and the collector slips over the headers and is loose. How do I get a better seal on the connection point of the header and collector pipe? I think this is part of the problem, in that I feel it's running a bit rich and the unburned gas in the collect explodes with the pressure drop when it shift. Is this the problem that I'm having, or can someone shed so light on what my problem is and how to correct this. It's a bit embarrassing to be driving a cobra, knowing it catches lots of attention and shift up and the car pops. I'll also take any suggestions on how to better adjust the Holley Carb, 4 barrel, double pumper, I think it's a 950 CFM.

[mpanten]

Sounds like bad gaskets for one. First thing I would do is replace them with the Remflex gaskets.

[mickmate]

Yes I'd start with gaskets on the heads to see if they're leaking or need replacing. Then I'd go after the leaks on the slip fit joints. I have some neat little brackets for those joints you might like to see.

[Dirty Harry]

I had a similar problem and I put new gaskets between the flange and the head, as mentioned above, then I spread Permatex Hi-Temp Copper on the pipes where the slip fit takes place. Problem solved. Keep a watch on how tight the header bolts are. If they loosen and begin to leak, the problem invariably worsens.

[Skipper]

I thank you very much for the quick reply. I try these out and keep you posted.