I'm looking to upgrade rear brakes to combine with my front 300zx bbk setup. Is there any info other than mattys kit or a step by step parts list to do the conversion to 300zx rear for the 4th gens

 

No. Its a pretty expensive and single-source-dominated swap that will cost you more than its worth. $1000

 

I was also wondering about bigger brakes for the rear on the 4th gen. I've got athe Z31 upgrade on my 3rd gens rear brakes and having done that made my rear rotors as big as the front stock rotors which are the same from 89-01 iirc. I wonder if that can be done on the 4th gen...

 

BlehmCo makes a rear BBK.
http://www.mattblehm.com/rear_kit.htm

edit: oops you said other than matts kit.