UPDATE/RESOLUTION Turns out all the SFP's were fine — there apparently was some issue with negotiation with the switch on the build bench. To troubleshoot, I had a DAC cable and plugged that in between sleds.  Lit right up.  So then I plugged the sleds into each other and all the SFP's for base-T, even non-Dell, worked fine talking to each other.   Then tried another switch and the SFP's lit right up. In my research on this problem, I had heard about some of these SFP's needing to be manually set to a speed to be backwards compatible with some switches, but in places such as iDRAC configuration, the link speed configuration options are dimmed…. probably because iDRAC is sharing those NIC's so it can't/shoudn't override the system configuration.  I don't see another place to configure this, however. I hope that in newer Dell software that (1) the presence of SFP's is better communicated, and (2) the status of a present/inserted LOM/SFP could also be shown (such as no cable/network connection).
Could anyone verify which SFP's work for the C6320?   Or is there somewhere to activate/configure the ports?  When I look in BIOS/iDRAC/LifeCycle I believe that I am only seeing the default LOM slot info as if nothing has been inserted. I have tried PF911/Dell Part 407-BBOS which on Dell.com has C6320 listed as compatible.  I tried  both a Dell branded module as well as third party module that said it was compatible/interchangable with 407-BBOS. I also tried a random Avago ABCU-5700RZ that I had laying around and that didn't seem to do anything either. Can't get them to work on any of 3 or 4 sleds either so that makes me think the problem is incompatible SFP's unless there is some way to enable/disable them that I can't find. Should there be some sign of life for even an unsupported SFP?  These SFP's just act totally dead.  No lights, no information or errors when I am looking at LOM information in settings/idrac etc. I am assuming they should show some life even in pre-boot, so let me know if that is a mistake.  Lifecycle Controller needs one of them to be active for connectivity to that so I would imagine that they should be visible without an OS installed on the sled.  
SFP's for C6320 Sleds - can't get them to light up