You may be asking about delivery time. We do not sell head gaskets so we do not know. You may be asking about the size of Subaru head gaskets. The answer is "long enough to fit". You may be asking about the amount of time they are guaranteed. Check with your dealer or warranty manual. Lastly, you may be asking how long they will last. Reminds me of my childhood when I was really worried about the potential for our house to burn down and wanted to know when it will burn. The answer is that it may never burn down or may burn down tomorrow. Same answer for head gasket malfunction.
The 2006 Subaru Outback is 15 ft. 8.7 in. (188.7 in.) long.
The 2012 Subaru Outback is 15 ft. 8.2 in. (188.2 in.) long.
The 2002 Subaru Outback is 15 ft. 7.4 in. (187.4 in.) long.
The 2010 Subaru Outback is 15 ft. 8.2 in. (188.2 in.) long.
The 2009 Subaru Outback is 15 ft. 9 in. (189 in.) long.
The 2014 Subaru Outback is 15 ft. 9 in. (189 in.) long.
The 2008 Subaru Outback is 15 ft. 9 in. (189 in.) long.
The 2004 Subaru Outback is 15 ft. 7.4 in. (187.4 in.) long.
The 2011 Subaru Outback is 15 ft. 8.2 in. (188.2 in.) long.
The 2005 Subaru Outback is 15 ft. 8.7 in. (188.7 in.) long.
The 2003 Subaru Outback is 15 ft. 7.4 in. (187.4 in.) long.
The 2013 Subaru Outback is 15 ft. 9 in. (189 in.) long.