Wiper Trico Blade Holders

[Pacecar]

I am seeing two styles of the Trico wiper blade holders - the part of the wiper that holds the rubber blade. One style is flat which is what I have on my 1968 and April build 1969. Just saw a late September 1969 original car and it had the point style or where the sides come to a crest like on a roof line. Which is the correct original style or is it another early vs late year change ? thanks

[Edgemontvillage]

You might find this thread helpful:
http://www.camaros.org/forum/index.php?topic=13184.msg112753#msg112753