You could go or call a GM dealer parts, they might have them.
There not a normal screw you’d find at a hardware store, I don’t think anyway when I’ve removed my MAF to clean.
2007.5 GMC "Black" Sierra SLT 3500HD SRW C.C. 4X4 LMM Z71
DIY stock airbox mod, aFe ProGuard 7, OEM drop-in
EFILive ECM ATP - Heavy Tow Tune with Turbo Brake
EFILive TCM Duramax Tuner
DHD Cold Side High Flow Intake Pipe
DHD PCV Re-route
2007 GMC Yukon Denali "BLACK" 6.2 gasser, DIY stock airbox mod, K & N OEM drop-in, Airaid intake tube, EFILive TCM tuned