my @fields = qw(Year         A2
                Month        A2 
                Day          A2
                Request_Seq  A4
                Request_Type A2
                Record_Seq   A2
                Record_Data  A1486);

my @keys   = map $fields[$_], grep $_%2==0, 0 .. $#fields;
my @values = map $fields[$_], grep $_%2==1, 0 .. $#fields;

my %data; # bad name. we should know better. ;)
@data{ @keys } = unpack join("", @values), $foo;