does anyone know if the fenders and grille for the round headlights off of a 79 datsun 210 will fit on a 80 datsun 210 with the square headlight setup??

You can do it, but you need a fair few panels and peices off the '79.
Parts:
Front guards
Bonnet
The bit between the bonnet and windscreen
Grill
Front apron
Headlight supports
And the bumper brackets are different between the two models also, same bumper, but different brackets.

I like it when people do this conversion, it is sort of like an old school strawberry face conversion. I have retro-fitted the square headlight sunny dash into my '79 round headlight sunny, but I have a nice set of Autometer guages to complement it

Yeah. It does fit but you have to get the bases for the round headlights. After that it should be easy. Just take off the square headlights and grill and put the round ones on.

does anyone have the parts that BAD310 has told me i needed?? I really want to do this conversion.... thanks