I can agree with oak. Are there any oak trees where you are in Il.
When I pass through that state I see a lot of corn.
The only thing I see in oak is the price, now if you were here in Mo. I'd cut you down an oak tree and give it to you cause I cut them down for firewood.
I'd consider treated wood unless you need stronger wood. I guess it would depend on how you intend on using the truck.
I burn up hickory trees to.
Dan