C6 brushed 400W fan with that big Siemens module uses 'PWM Electric' logic, C7 brushless SPAL uses 'PWM EV'. Pull a '14-up Corvette tune from the repository for a look at the differences.
The C7 Stingray fan is 500W (15-81913). C7 Z06 fan is 600W (15-81914)... and about $100 cheaper(?!). The shrouds and blades are the same, only difference is the motors.
I'm using an E40, haven't tested it yet, I have all the major parts on hand (still gathering the last wiring bits and pieces). The C7 aux distribution block is compact, fits in a easily adapted bracket, has a nice secure cover, offers a B+ IN post, a 225A fused ALT post, an 80A FAN post, and a 100A post, used in the C7 for the EPS, but could be used for any other suitable high current accessory if you ever needed it.
Fan assy:
ACDelco 15-81914 ($190!)
Harness connector:
https://www.ebay.com/itm/233178180273
C7 aux distribution block/bracket/cover: 23173653/23173654/23491757
I really, really needed the fan connector on the driver side which would have meant rotating the C7 shroud upside down which would have put the flappy-vent things upside down and therefore non-functional... so I cut away everything but the fan itself. I picked up a 4.2L Trailblazer fan shroud ($22, new) and trimmed off anything that wasn't needed. I'm blanking it off with .063" 3003 sheet and mounting the C7 fan as if it were just another universal aftermarket unit.