Yes 65-75 shot is ok on a stock engine. Just make sure your compression checks ok. That's a thing to watch for.
You'll need to retard your timing accordingly. 4-6 degrees I think. But look in the manual. Also run plugs that are 2 steps colder. NGK makes some good plugs for this.
Mini FAQ
Zex is nice because the install is cake. With no experience, expect to spend about 4 hours installing.