68ratvt is right, a puller is so much more efficient than a pusher, but I bet you did it because you have no room back there for one. Is that the case?

If you can put a puller back there, do it, with a shroud for sure. But if you have to use a pusher, put the very biggest one you can fit in there, and of a good quality. I'm partial to SPALS myself.

Don