I asked Altrec how tall the brackets were.  Here is their response:

Thank you for the email. The towers are high, about 8 inches off the rain
gutter. I hope this helps! Please let me know if you have any other
questions.

Sincerely,

Greg
Altrec.com
800.369.3949 

-----Original Message-----
From: TStone8359@aol.com [mailto:TStone8359@aol.com]
Sent: None
To: customerservice@altrec.com
Subject: Customer Feedback Form

recipient: customer_service_survey
Contact : YES, PLEASE CONTACT ME
Comments : I have a question about the Quick-N-Easy brackets; how tall are
they?� I have a '91 VW Vanagon (not camper) and want to make sure they clear
the roof by a safe margin.

Thanks!

Tom