if i only have a 60mm spot for a case fan on the front of my case, will it be helpful to use a 60mm to 80mm converter and use an 80mm fan? I know an 80mm fan pushes more air, but will it be more effective?
No it will be a waste of money (cost of the adapter, and higher price of an 80mm fan).
If you restrict the airflow out of a fan by necking it down to close to 50% (80sqrd vs 60 sqrd) the airflow will drop accordingly, back pressure will increase, fan life will drop, noise level will go up. Bad option.
If you have room to mount an 80 mm then you should be able to cut out a bigger hole for it. Now you're looking at an improvement in cooling and probably less noise.