i ordered part number 922-5796 from mac-pro.com
and the part i got in the mail says 190W
while the one i pulled out of my computer says 160W

whats the deal? will this part still work?

the serial number you gave me matches that part number exactly. Typically they no longer produce the 160w so if you replace the part you get upgraded. This is typical for lots of parts on lots of systems across every platform. For example some of our HPs at work were shipped with a 30gig HD. Well, HP no longer carries 30 gig, so when I order a replacement under warranty I get a 40 or a 60 gig sometimes now instead. They no longer stock the lower wattage PSU because there is no need to, because the 190w probably works in all models and supplies enough power to the larger screen imac.

It should work.

yea, well it does say
"MAXIMUM OUTPUT POWER"
that definitely infers that in can be less

i installed the new power supply
and so far
everything appears to be working perfectly

its so nice to have my 17" screen back
thats what i notice most
much better resolution also it appears

thanks for all the input everyone