Any idea what this canister is?

[gdmorey]

This part is connected to heater hoses coming from the water pump area and the box on the firewall. I looked underneath and it looks like the cracked holder May be a sort of block heater?

Any ideas what this is and what it does?

 

[FDChappie]

Doesn't like a factory item to me, I concur that it's probably a block heater.

 

[jeff campbell]

Yup ! An old block heater !

 

[1975IH200]

Yeah, I bet napa still stocks those.

I installed one once, works really well in cold weather.