if your pusher fan REALLY moves 2000cfm, your problem is there. you need at least 3000+ cfm to even get close to cooling anything for any length of time.
most aftermarket fans are FAR from accurate on their CFM ratings.
you need a bigger fan, one that draws lots of amps, to stay cool.
and since yours is a pusher, [pullers are WAY more efficient] it needs to be bigger than you think.
just my opinion, your results will vary.