This is when I love the internet, and have learned to hate the parts monkeys. Granted, the carquest I go to in my town doesn't have monkeys, they actually have good people, but most places just have monkeys.
<!-- BBCode u2 Start -->http://www.gorancho.com/products/applications.stm" TARGET="_blank<!-- BBCode u2 End -->
And specifically (these are all PDFs):
<!-- BBCode u2 Start -->http://www.gorancho.com/documents/specifications_1.pdf" TARGET="_blank<!-- BBCode u2 End -->
<!-- BBCode u2 Start -->http://www.gorancho.com/documents/specifications_2.pdf" TARGET="_blank<!-- BBCode u2 End --> (compressed, extended, travel, mounting codes, and valving)
<!-- BBCode u2 Start -->http://www.gorancho.com/documents/specifications_3.pdf" TARGET="_blank<!-- BBCode u2 End -->
So, best thing I've found to do is look stuff up and really look at the numbers, and see if they will work.
They also have crossreferences of shocks and vehicles:
<!-- BBCode u2 Start -->http://www.gorancho.com/documents/rs5000.pdf" TARGET="_blank<!-- BBCode u2 End -->
<!-- BBCode u2 Start -->http://www.gorancho.com/documents/rs9000.pdf" TARGET="_blank<!-- BBCode u2 End -->
<!-- BBCode u2 Start -->http://www.gorancho.com/documents/shocks.pdf" TARGET="_blank<!-- BBCode u2 End -->
The parts monkey probably looked at the last part, and went as far as that.
You can take the part# for the 4" lift, and then find the shock with the same mounts that's 2-3" longer extended, and hopefully short enough compressed as to not use IT for a bump-stop, and you're all set.