ok guys i need a little advice/ help! i recived my fan shroud via ups and its time to install it.im running the old clutch fan which measures 19"that i want to get rid of, and i have a flex fan im thinking about using my ?'s are the opening for the shroud measures 19 1/2" and the flex fan measures 17" is that gonna be alright to run and pull enough air or does the fan need to be bigger? im worried if i go bigger is there gonna be any chance the fan hitting shroud if motor flexs/moves ? and how far does the fan need to be in the shroud for proper performance? i've never addressed fan shroud's before so im in the dark any help is appreciated!