That amp is indeed doing what it says. I've used two of them. That's a great little driver you have too. I'd buy another and just swap them out. As Sean's said, vent is small, but you'll never hear it in the trunk.
To keep it ported you'll need to add an external port. If ID recommends a 2" port they should be shot. Absolutely absurd.
If you are happy with the sound then just get a different amp. It will be cheaper in the long run. Sell what you have and go for it.
I will also add that in general ported 8's are not logical in single units. I built an enclosure with a large enough port for a single 8 and took pictures to show the point. Regrettably this was about 8 years ago and I can't find the pics online anymore. Either way, that 8 ported took more space than my 12" sealed and had way less output.