Seam sealer for firewall/cowl?
 

What seam sealer would you guys recommend for the cowl and firewall area? I'm cutting out and replacing rusted sections on the pass side. There are some gaps between inner and outer cowl structure that I need to fill, so I need a seam sealer that is thick and will build in those areas without running out.

I'm considering Fusor 805HD but can't tell if it will fit a normal caulk gun? How about similar products at the local NAPA that I can substitute?
Any voices of experience?

Edit: Bah, meant to post this in body section.

I would use a brush able seam sealer for large areas on the firewall. I have had good luck with transfer brand sram sealer

Dang auto correct transtar brand.

I'd be curious to hear what everyone has to say on this, too. I'm also getting ready to prime and paint my underbody and cowl. Will need to settle on a seam sealer soon.

Depends on if you want a factory look or not. Factory was brush able. Just went through this on the replacement panels. Tried to buy 3M brush able but got stiffed by he company so just went to the local paint and body store. Bought the cheap can. Applied it with a stiff brush. Came out nice. Cant remember the brand but it's got a pic of a 57 TBIRD on the label.