i bought 6 injectors and the fuel rail with the fuel pressure regulator from a 03 bonneville, k engine and the dam fuel imjector connector is different that on the injector, i thought all the fuel injector connectors will be the same? when did they change the size of the connector?

I guess they changed styles. I think the pre 03 had Bosch style, I think.

would you think these injectors would still work properly if i get the correct fuel injector harness for them

If they take the same voltage to fire and mounting surfaces are the same profile. Figure out what you've got and do a little research. You can find anything on Google.