2X on the Racetronix, purchased direct from Racetronix or one of the vendors who support the forums at LS1Tech.
Also get the upgrade electrical harness.
http://www.ls1tech.com/forums/index.php
There are a number of differences with the 3rd and 4th gen Firebird/Camaro fuel pumps that a lot of vendors are not
aware of.
If ever a vendor tell you they have a pump and there is not any difference. Walk away.