How low can I go??

[ab_70chevy]

This is my first post! Iv been coming back to this site for a couple years and Iv just recently aquired my Dads '70 Long bed. And its not low enough! I dont have the money to bag it like I want right now, but I was wondering how low I could go with a static drop? The front has 2" spindles and 2" drop springs. The rear has 2" drop springs with a 1 1/2" block. Im happy with the front for now but I was curious if I could swap the rear 2" drop spring for a 5" drop spring with out a c notch. Iv read that I would need an adjustable pan hard bar. Which is fine Im cool with that. That would make it a total of 6 1/2. Is there any other problems that Im going to run into or anything that I need to look into. I'll try to post some pictures of it when I get home.
Thanks for any help fellas
-Andrew