Is it normal for a 225 to...

Did you check to see if someone put a playing card in your spokes without you knowing it?
Just kidding!
I actually think it's the fan hitting something that shifts when you drive it and it contacts the fan. Look for wear marks on the fan blade tips.
I'll bet your motor mounts are toast.
Get someone to power brake it until it makes the noise while you listen from under the hood.
My second guess would be torque converter bolts hitting the tin cover either on the bottom or the starter shim has come loose. Check to see if the starter is loose and the tin shim is behind it and in it's proper place.