In order to have the Sun Enterprise (TM) 220R hardware and Sun Enterprise (TM) 420R hardware
display the correct name, you must change the eeprom settings 
as follows:                              

Sun Enterprise 220R

As Root:

# eeprom banner-name="Sun Enterprise 220R"

# eeprom enclosure-type="540-4284"

# eeprom energystar-enable?=false

Sun Enterprise 420R

As Root:

# eeprom banner-name="Sun Enterprise 420R"

# eeprom enclosure-type="540-4115"

# eeprom energystar-enable?=false

Once this as been done, the banner after POST will show it as the correct 
machine type. Also, the prtdiag -v output will now display it as the 
correct machine type.                              

Note: That uname command will still show the machine as a Ultra 80 for the 420R and Ultra 60 for the 220R.