I purchased a set of 3KGT brake caliper brackets, and took some measurements so that other members could reproduce these themselves. This may be documented elsewhere, but I never found a good set of measurements that actually made sense. These measurements were taken from my brackets with a Snap On Blue Point dial caliper. Some of the measurements were rounded to make the math add up, but overall the measurements should be accurate to >.010". Please PM me with any questions.
Edit 1: Each of the holes in the bracket are threaded. The first set of bolts go through the steering knuckle and bolt into the bracket. The second set of bolts go through the caliper and bolt into the bracket.
Edit 2: I've already received a few PMs about what rotors these brackets are compatible with. The rotors I have are just typical 3000GT discs much like these: click
(Stock rotors left, 3KGT rotors right)
Edit 3: This may be obvious, but it's worth noting the 3KGT rotors are 5 lug, yet they are pictured on my 4 lug Galant. Curtis, being the nice guy that he is, went out of his way to do a little writeup on how to drill the 5 lug rotors to fit 4 lug hubs ---> Drilling 5 lug rotors for 4 lug hubs
Edit 4: The brackets I posted measurements of will NOT work with the Cobra rotors to my knowledge. The measurements for 3KGT adapter brackets that use the Cobra rotors are mentioned in this thread ---> click and are pictured below: