not many..
my first 5.o i had i tried deiffernet ones, BBK, MAC, Hedman
they all suck and all rub.
then i did a manual swap and went shorties
but really, there was a write up in 5.0 mag that the best all around header is the unequal length shorty headers.
each different style header had its goods and bads, but the unequal length shorties made the most power through out the RPM range.
so unless your doing a blower, id stick with shorties..
equal length shorties will flow a little better up top, but will not net you as much torque as the unequal length.
also the unequal length are alot easier to install.