I have a 78 280 2+2 that has an engine with NO CATALYTIC this is factory (gotta love it) any way my question is, it has a dash pot with a white plastic fitting on the top that appears to need a hose attached. The problem is I can not for the life of me find any thing that tells me where is gets hooked up to or even if it does get hooked up to anything at all .I do know that when I blow air into the end with a hose is does make the car accelerate a little. Does any body have any ideas about this?

Only the California cars (like mine) had a catalytic converter. No hose goes on that little plastic screw-on cap. It's just a vent.