I say put a dust pan on both sides... Seriously, fix the cooling system and if you still feel like you need one of these, then run it all the way across and run it under the radiator support so it will act to create a vacuum for the radiator to hopefullypull more air thru it. the whole front end on the 68 B body is open,so how much more air do you really need. Figure out what is making it over heat now and fix that first. I don't think what you have in the picture will be much help if any.