kz750 tank on a kz650?

Will a kz750 tank from the same time period work on a kz650 frame or will it need modification?

You need to be more specific about what tank you are trying to swap to what bike. Put your bike in your sig line that always helps.

many times you will run into issues such as carb to petcock clearance. I threw some 650 boots and carbs on my 750 once to try them and soon realized that there was NO room for the fuel line because the petcock literrally sat on the carbs

I put a Z1 900 tank on my H1 500, massive tank, looks awesome

del