I have a 76 280Z with the L28 motor and a 77 280Z with the L26 motor in it. I am looking for a full engine rebuild kit for both engines. Does anyone know where I can buy one?

Also I am looking for driver and passenger floor panels. If anyone knows where I can find these parts would be great. I am in America, I really dont want to have to import anything.

Rockauto, napa, any parts store or machine shop can sell you a rebuild kit. I used kits from pretty much all of them. Racetep.com if you want a performance oriented kit.

Floor pans, afik Zed Findings in Canada is the only manufacturer but if you don't want to order from canada, msa, (zcarparts.com) as well as a few other z specialty places sell their panels.