what thickness of sheet metal is noamaly used for the cowl and firewall what is the easy way to fix a rusted out cowl were the heaters fresh air duct goes thru the cowl . can you buy that part or do you have to fab it if I can get it it would be nice if not I dont like fabin stuff take the value away this not nothin like a chevy my brother And I restore late 60s chevy trucks and you can find any thing for them. but these cars are a big pain in the -ss ya know any info would be nice thanks wootdog oh by the way 71 mach 1