I’m looking for a Cap, topper for my 2012 Regular Cab 8’ bed and found a used ARE Sierra 8’ cap at a dealer. He claims it will fit but ...

I’m looking for a Cap, topper for my 2012 Regular Cab 8’ bed and found a used ARE Sierra 8’ cap at a dealer. He claims it will fit but the rear corners will be 1/2-3/4” wider.
Anyone put one for a Sierra on a Silverado that can post a picture?
He’s wanting top dollar and 3-1/2 hours away but the color is correct.
Another ARE dealer I called said he wouldn’t install one from a Sierra on Silverado.

So I bought it because the color matched and what I noticed was the rear radius above taillight is a little wider at side and back about 5/8” but doesn’t affect back window closing.
And the front of sides at top of bed rail seems to be a hair high, slight gap. Not sure if this is an anomaly or my bed rails been abused.
Overall I’m very happy with it.
It seals tight on the bed rail.

I bought a Leer cap from a 2013 Sierra for my 2011 Silverado. Just like you said the rear corners are just barely wider. Other than that it’s a perfect fit and functions 100%. For what I paid I’m very happy.

I bought my topper from a 2012 gmc sierra and put it on my 2010 chevy Silverado . just the little gap in the back by taillights.
I paid $200.00 for topper and bed rug that matched, Well worth having ,

It's actually better to get a camper shell meant for a Sierra, since it would be more professional grade.

^^^^ somehow I knew that was coming.