What to use at heater box

[Dalejrfan]

So, I've got the motor out in my '79 Blazer and I took out the heater box at the firewall. I'm planning on painting the fenders, firewall, and the inner fenders. Once that is done what should I use to seal up the box? Black silicone or what? Any help would be great. Thanks!

 

[dyeager535]

I used black RTV.

 

[Jason4x4]

http://cgi.ebay.com/ebaymotors/A-C-...uck_Parts_Accessories?_trksid=p4506.m20.l1116

 

[Papi Grande]

i'm cheap and RTV seemed to be a little expensive for me so I got a tube of roofing sealant(home depot 2.49 I think), black of course, and sealed it up tight.