So i was going to plug my receiver into my new PC via HDMI, but there is no HDMI port on the mobo. This may be a terrible question but if i plugged my receiver into my GPU hdmi would that take sound.. or no?
If your gpu does sound and your receiver splits audio and then video back to the tv/monitor then yes.
You can even use a 3.5 to RCA adapter and not deal with HDMI. Dollars to doughnuts, you wont hear a difference.