can buy a z but owner says needs a fuel pump to run. got a zx pump. will it mount handily on a z or will I need to duct tape somewhere long enough to get to my house.

If the Z is EFI and the fuel pump is from a 79-83 zx you won't have any issues.

If the Z is carb'd-don't waste the energy trying-way too much pressure and flow.

Will

Check the condition of the rubber hoses that connect to the fuel pump too. those are likely to fail. Check all the rubber hoses on the high-pressure lines.