Cirrus 820 mounted on GMC

Cirrus site says the 820 height is 9’8”. I think you are going to be very close. I’d also make sure the 12 door is really 12 from bottom of the door open to floor. If it is just a little off on adjustment, you could lose a few inches.

I have a 2015 GMC 3500 HD with an Arctic Fox 990, which has a basement, and it measures 11’9”.

Well I have my Dads 2000 Chevy 2500 and his 2015 Chevy 2500HD. Both 4x4's.

The 2015's tailgate sits a good 6" higher than the 2000. The 2000 doesn't need running boards. I can't get into the 2015 withOUT the running boards. The seat on the 2000 is at "sit down" height. The 2015 is at "belly button" height. If I forget and think I'm in my 1500, and slide out of the seat, it HURTS to hit the ground you drop so far.

I’m sure with a little bit of googling you could get the camper dimensions and truck bed height and add them together and then add/subtract for AC, truck squat, etc.
there’s a good chance it will fit. Cirrus campers “look” a bit shorter than AF campers and I could get an AF with full height roof AC on a 3/4 ton Ram in my 12’ door, barely…only with no air in the bags.
And remember if it’s infrequent, you can gain some clearance by airing your tires down too.

Thanks guys I am up in Canada right now and don’t have access to my truck I was just wondering if anybody had a 2015 GMC HD with a Cirrus 820 mounted on it that could give a close measurement. Sorry for the late reply but believe it or not where I am it’s a Third World country in terms of communication.

If neither of you noticed, she doesn’t have the camper yet, so can’t just go measure.
That said, get the height of camper from the spec sheet, add for AC if needed, measure the truck bed height and that is worst case. It’ll be a bit shorter with the suspension loaded.

Trucks haven’t gotten 6” taller nor do garage doors need to hang down 6” into the opening.
Gut says it’ll fit. Our old AF camper (which the Cirrus campers look to be not any taller, possibly shorter) with a big box AC not low profile fit in our 12’ garage on a Mega cab 4x sitting on 35s….barely. I couldn’t air up the bags until camper was out.

Measure first then you will know. Get the actual height of the door and camper.
Or...If you get going fast enough, it will fit.

Most likely no. I would estimate that you will be closer to 12'6" but that depends on a lot of factors.

Is this a 2002 or a 2022 truck? The trucks have gotten about 6" higher.

Does the garage have an overhead door? You lose about 6" of opening height with an overhead door. Even if you push it up past "open" it never quite clears the opening.

Easily! No! Measure carefully. Have a spotter. Drive slowly!