1972 F100 4x4 suspension height

[rgoot01]

I have a 72 F100 4x4 that I purchased 8mos. ago. It has 265/75-16 on 16x8 wheels. The tires measure 32.00x11.00x16. National tire and wheel states that a '72 with a four inch lift can accommadate 33.00x12.50 on a 15x8 wheel. Knowing this I have assumed that the suspension is not factory height. My question is "what is the factory suspension height on my '72 F100 4x4?" Also, my rear spring packs have 14 leaves. I need to know where my suspension is so I can buy the proper degreeed C-bushings.

[lifted72]

From the factory you can clear 32's with ease, and with a four inch suspension lift you can clear 35's. I personally have 4" suspension and 3" body and my truck sits on 37" tires and im sure i could fit bigger. I bought my truck with a 4" lift and 35s on it.