I recently bought a green 2002 Toyota Tundra SR5 Access Cab with 236,000 miles on it for $3,700.  It is a southern truck in good shape, no rust, no dents, clean intact interior.  Just faded paint and needs some maintenance work caught up.  I have the 2UZ-FE 4.7 V8 with automatic transmission. The only code present is for the O2 sensor.  My question is about spark plugs. My Tundra calls for copper plugs but later years used iridium plugs. Is there any reason I should stay with the OEM copper plugs vs the iridium plugs later years used? Also I see multiple gap sizes on offer for my tundra, what is the correct gap I should buy? I have already changed the timing belt w/ Aisin kit, shocks and struts, checked and bled brakes, checked hoses, checked ball joints, replaced serpentine belt and idler pulley. 

Thanks in advance