MTU Problem on Cisco 7606

Hi everybody,
I have change my core router from 7206 VXR to 7606 with RSP720 since last 1
I had GRE Tunnel in 7206 with one of my regions with this config:

interface Tunnel1

ip mtu 1500
ip policy route-map clear-df

I have copy this config to new 7606 with the same config but now I have
Problem with page load.
For example totally does not work.
I change Tunnel interface config to:

interface Tunnel1

ip tcp adjust-mss 1360
tunnel mode ipip

But again does not make difference, for example solve but put
another site in trouble.
I must notice that my region side router is 7206 VXR and we have not change
that router, It is the same as before was.
The question is what is different between 7600 and 7200 in MTU?
I change "*system jumbomtu*" to *1526* on 7606 but it does not make any
Would you please help me in this field?

IOS on 7606:


IOS on 7206: