MTD 10 HP Tucumseh Snowblower?

Replacing the head gasket OEM 34041B
Do I need new bolts for first time replacement
What should I torque them to?
I could see some head bolts had washers and others didn't was due to bolt length of poor manf?

Can I clean the exhaust valve easy? I'm not sure that it seats that well and my leak was adjacent to it.

Thanks in advance for any help!