I slid the clip all the way to the bottom of the metal rod on my toilet assembly, but the water level in my tank is still about 1 1/2 inches over the water fill line and is overflowing into the tube with every flush. Is there anything else I can do? Thanks in advance for any help.

You need to lower the flush assembly. Best to remove the flush valve, release the grey circular clip and push the top down. Did you just install this? Did you follow the instructions on setting the float level?

I will try your suggestion; thanks! I didn't install it. I think it has been happening for quite some time and I just found out about it when I opened the tank to check something else.