02 Envoy/TB fan clutch difference???

[jaguarjoe]

I have an '02 4.2L I6 TB with the electrical fan clutch. While touring the local P-n-P, I came across an '02 Envoy that also had a 4.2L I6. I thought they were identical engines but I was surprised when I saw that the Envoy's fan clutch was mounted in front of the fan and was straight thermostatic, no wires to it at all.
Why were there two different designs and can the non electric Envoy set up be used on the TB?

FWIW- a 12" Crescent wrench fits that 36mm nut perfectly.

 

[The_Roadie]

08 went to the thermostatic clutch on all models still in production. Your sighting must have been upgraded, but the factory didn't do it.