What does my chipper weigh> Plate purchase time..

[Hoosier]

I need to get plates for my chip-more drum "chuck-n-duck" chipper and cant find any kind of weight on this unit? It is a 300 in-line 6 ford. Anybody have an idea, I currently have 5000lb plates on there but would love to make it lower for various reasons (keeps combined GVWR lower etc..)

Here is a photo for your review,