Rear Window Gaskets

Guys, I got this question from a Mopar friend.. He is working on a 1968 FB Barracuda for his brother.. He is in search of a rear FB window gasket and asked if there was any difference in the 67, 68 or 69 rear window.. I told him I thought they all were the same but I knew someone on here could answer our question.. Yes it's on a Barracuda racecar... Thanks in advance for your replies.. Mack