briggs acting weird,

[Russ2251]

i see cardboard catching fire from the heat.

At the most they will burn through. They will not catch fire.
I use 1/32" gasket material on my custom exhaust system(s) with ZERO problems.

 

[CaptCanadia]

Good point. It would still be good for the intake though.

 

[Bluethunder3320]

ive made a exhaust gasket on a 2 stroke out of a waffle box and after running it hot.. still there.

 

[redsox985]

Ideally, it'll form an airtight seal and couldn't burst into flames due to lack of oxygen. Like Russ said, it may burn through, but shouldn't flash.