So the new post mounts I got for my deck have an inside diameter of 3 1/4 x 3 1/4. I can purchase 40" 4x4s with the one end shaved down to fit but I need to shave down a couple 4x4 8' long. The 40" posts I bought are tapered for 11" to 3"x3".
Like this.
IMG_20150716_190458.jpg
Any suggestions on how to shave ~3/8" off of all four sides with decent accuracy to keep the post centered?