are you talking about the two fins that protrude down into the water from the suction housing or the slats on the actual grate that bolts into the suction housing. If it is the fins attached to the suction housing that would involve alot of work to remove the housing and you would need a new one. If it is the grate. Unbolt it and buy a new one. Mike at mikes pump and speed in houston sells a loader grate that will help your performance for about 80 dollars. If they are the fins attached to the suction housing I would try to file them down best I could and go. I really don't think they would hinder the performance too much. I think they are more designed for stability in turns. I would highly suggest you get a loader grate one way or another. They help and Mike is about the cheapest around. here is a link to his website www.mikespumpandspeed.com Some pictures could probably help if you have any.
I'm spinning a jacuzzi yj also and have my factory grate still if you want to stay factory.
Kris