Space around my fan shroud?

I have a semi-custom Be Cool radiator that is notched so that it sits down between the frame rails, but is wider above the rails. The core is 24"w x 18"H.
I found a good price on a SPAL 30102052 11’’ Dual Fan, pictured below. It is just over 23 1/2" W x a little over 16" tall. It's a puller with approx. 2,700 cfm.
Is it a real concern that the core will be a 1/4" wider on each side as well as about 7/8" taller top and bottom? Do you really need a shroud that comes edge to edge? I'm sure it would be more ideal, but is it a big deal?
-Thanks