Basically the Avalon engine, auto transmission, brakes, are the same as the Camry with V6 option package. The 4-cylinder Camry has different brakes, front springs, trans and a few other things. The frames are the same for all cars. The Avalon’s trim and interior may be different. It may have come with a standard theft prevention system, ECU, the wiring might be a little different. Might have an improved ABS system.
A good way to tell if the cars use the same part is to go to a site like
www.rockauto.com and compare part numbers. V6 Camry and Avalon.