I also used Sid's 4 inch drop axle. I also went with his modified steering setup and 3 inch lowering blocks in the rear. I removed 2 springs from the front and rear to drop it just a little bit more. I have 15x6 in rims with a 3.25 back spacing and 235/70/15 tires on it. Everything clears well and it was a cinch to put on. One thing that you will need to get is 4* caster shims. I have an extra pair since my local napa wanted me to buy 6 of them when I only needed 2. I ended up buying them online and bought 2 extra just in case.

Here's a picture of how the front end sits.

http://i138.photobucket.com/albums/q268/cotsi95/chevy%203100/frontdrop_zpsd5d2474d.jpg



52' Chevy 3100 5 window