Auto body repair & detailing: welding in floor panels, mechanic, chevy

Question
Hi Brandon thank you for your time. My name is Dave and i am a mechanic by trade but i have knowledge of body repair but i not sure on this repair i have a 1979 chevy p.u i am restoring and i have to replace the driver floor panel.I have cut all of the rusted medal out. My question is do i cut the new panel exactly the same size as the floor and weld or do i over lap the new panel on the old and weld  

Answer
Dave,

What you want to do is over lap the new floor pod about 1 1/2 to 2" this will allow you suffice room to weld to and also is easier to line up when setting in place. I suggets going under the truck after and undercoating where the two panels meet.