Author Topic: Y Duct revision  (Read 3300 times)

139tech

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Y Duct revision
« on: March 16, 2024, 12:00:11 AM »
Question about the defroster Y duct on 69. Just pulled mine and it is part number 3949974. It is the original. My car is a 4th week March car and in the assembly manual GM introduced a new Y duct in March of 69 part number 3973729. My duct openings don’t meet the dash cutout properly and am wondering if anyone has any insight into GM’s March cut in 3729 duct. Was it a better fitting duct? Wondering if I should replace mine with it if that’s the case. Thanks
1969 Camaro SS
396 L78 M20

william

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Re: Y Duct revision
« Reply #1 on: March 16, 2024, 02:17:33 AM »
There was a service bulletin on the change.
Learning more and more about less and less...

139tech

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Re: Y Duct revision
« Reply #2 on: March 16, 2024, 02:27:44 AM »
Fantastic, exactly what I needed! Thank you so much!
1969 Camaro SS
396 L78 M20

john302

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Re: Y Duct revision
« Reply #3 on: March 23, 2024, 10:51:56 PM »
Every duct we install they  never fit . They warp overtime and lose there shape . We gently warm them up with a heat gun and move it back in shape . Works great