Is this possible? I have a Flowmaster dual chamber muffler sitting in the factory position fed by Edelbrock TES headers. It gets so hot that the gas in my tank actually bubbles and the tank becomes pressurized to the point that it fires the gas cap like a missel when you open it. Ive done all the checks and the venting system is working. The gas tank is warm to the touch and the factory heat sheild is in place. Also when this happens the fuel pump starts to scream. Any ideas?

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1987 T/A GTA 5.7L, Bored .020 and ported for .202 valves, edelbrock headers, flowmaster exhaust, JET STAGE II chip, Comp CAM, Adjustable fuel pressure, Airfoil, K&N filter, B&M stage 2 shift kit, and a home depot ram air(Hey it looks good and it works)

 

That sounds wierd... the muffler shouldnt be hot enough to do that unless its blocked off or something internally.

Check the fuel line, make sure its not sitting on the headers anywhere up front. I am pretty sure thats not possible... but couldnt hurt to check it out.

 

Do you still have the cat in place? Look and see if it's glowing too...you could be running too rich is about all I can think of.