When I replaced the cowl seal on my '72 Supreme some years ago, I didn't have clear directions on whether the slit should face towards the front of the car or towards the rear. I installed it with the slit facing the front. I just watched a video of a guy installing one on a '68 El Camino, and he had the slit facing the rear...does it really matter?

 

I think the slit faces forward, towards engine bay. Does it make a difference? I dunno but I wouldn’t think it makes a big difference. Do you have an assembly manual that you can refer to? I do like to use weatherstrip adhesive on them. I’ll check a car and assay manual when I go outside in a few.

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