56 Chevy Door Problem

[eyft23]

Hi. I was wondering if anyone can help me out.. I had to purchase 2 new doors and new vent windows for my 56 chevy and I am in the process of trying to install them.. my problem is that the vent glass does not fit correctly.. it seems to have way too much of a gap all the way around.. can someone help me out and tell me how much of an opening I should have between the outer and inner shell? is there supposed to be a seal from the vent glass to the shell? the vent glass is a brand new complete piece.. thank you in advance..