I wrapped my svt,s header a few months ago the smell goes away it's the curing process.
It helps underhood temps dramatically... I can actually put my hand on the header with it full temp and not burn myself ( instantaneously that is).
And I wouldn't worry about header deterioration unless u got some cheap ass thin walled piece
** I also used the silicon spray coating
02 sonic blue svtf...< modified addiction < DD
88 bronco II (x2)... < the twins
00 yamaha banshee... <will be the end of me