a Diff 65750061/1 share will find a block
Pools distribute Diff1 shares historically to give miners something easier to work on and to count so miners can be paid - now that pools distribute variable difficulty shares (higher for faster miners) they usually convert back to diff1 for counting shares and paying miners
https://en.bitcoin.it/wiki/DifficultyPools do not distribute shares.
You find shares and send them to the pool.
Difficulty does not effect how long it takes to calculate the hash, you dont get "something easier to work on", you just dont have to calculate that many hashes before one fits given diff.
Your miners calculate hundreds of thousands of hashes per second. Those match a certain difficulty (and all lower ones).
You choose a diff and send all hashes matching at least that diff as shares to the server.
You tell the server which number is yours, and based on that the server can calculate your hashing power.
If you set a higher diff in the pool config, your miners will do exactly what they did before, they will not calculate more or less or easier tasks or anything.
Your mining client will just send less of your hashes to the pool, and they will be rated higher.