Do you know how to scale a sensor in the software?
I wouldn't get too excited about a sensor offset until you have it running enough to drive. Once you get to that point adjusting any sensor is pretty easy.
I've bought all of my open air IAT's from here :
https://www.diyautotune.com/product/gm-open-element-iat-sensor-with-pigtail/
I've tested and adjusted them with Holley and Megasquirt systems. Dialing them in is really easy and nothing to be concerned about at the point you're at presently imho. FWIW, that sensor in original GM form will rarely if ever read erroneously. I scour the local yard for them but they are rare in stock form.
The link I attached give the ohm readings at various temps. Check yours against those numbers.