A couple of vendors are showing a five foam washer kit for the heater box to firewall installation for 64-72 Cutlass/442. Were those foam washers provided by the factory? The two vendors I am talking about are more heavy into Chevy than Oldsmobile. I don't see them shown in the factory assembly manual. I didn't see any trace of them when I took my heater boxes off, but I don't know if anyone had their hands in their before I did or not. Do they belong on Oldsmobiles?

 

There were no foam washers used. If you want to seal the bolts off, I would just use some soft rope type chalking