iMac 27", Mid 2010 (11,3 model) I have an iMac 27", Mid 2010 (11,3 model), "Core i7" 2.93 GHz. 4*2GB installed RAM..Plan to upgrade. 
Any thoughts, experience if 4 * 8 GB would work if upgraded to or is 16GB with 4*4GB max I can reach?
Thank you
According to everymac.com, the answer is a maximum of 4x8GB=32GB.

Crucial will sell you 2x8GB for $103.99. 

OWC will sell you 1x8GB for $39.99 or 4x8GB for $159.99.