Purpose of special washer

[Tinkerr]

I'm installing the heater assembly and pg. 52 of the 68 assembly manual shows a #7 spl washer. Any ideas on the purpose? When you order the repo nut and screw kit it doesn't include said washer. It looks like it goes between the blower cover and the firewall like a shim. Thanks

[Spooky]

https://www.amkproducts.com/search-result/?ser=3868762

looks like it is a seal in the shape of a washer

[67CruiseMaster]

Spl is split washer. Possibly of lock washer

[Tinkerr]

Ricks Camaro has a heater box to firewall fastener kit that has 5 nuts and 5 of those special washers. They weren't included in the kit when I put this thing together 10 years ago. I'm not sure where 5 of them go. In the assembly manual picture it appears 1 goes between the firewall and the heater box. What are the other 4 for? Thanks Paul

[jacmac]

Reading the AIM I see "P Washer"  "L Washer" "SPL Washer". I always thought "L" was a basic lock washer.
UPC-12 A5 note 8- L Washer is an external star washer for grounding purposes.

[Tinkerr]

I looked at a restored 67 Camaro today, when the owner reassembled the heater he put the washers(kind of a felt texture but firmer) between the firewall and the blower motor cover on each stud when it came through the firewall. I have never seen those washer used on any other Camaro or GM product for that matter. Has anybody else seen these washers on any original cars. Thanks Paul

[jvb6648]

I bought this kit. They're a "special washer", felt like material that goes on each stud as a seal or gasket.
https://www.classicparts.com/1967-74-Heater-Box-Firewall-Mounting-Kit/productinfo/HA-0132/

[Tinkerr]

That is a similar kit to the one Ricks is selling. I've never seen those washer used on any GM heater covers. I guess I'll order the kit. I'd like to see a original car to verify. The Camaro Nationals are in a couple weeks about 10 miles up road, I may wait until then to get a look at original car. Thanks Paul

[jvb6648]

This is how mine turned out.