What heads / milling combination will bump up the compression of a stock 4.8?

 

if you wanted to use your stock heads i would get bigger valves cut in them i seen in a few mags the 4.8 or 5.3 same thing pick up big numbers with the 2.00 valves cut in and a pocket port then while there off mill them .010 or so and buy a thinner gasket but more power is to be gained with flow than compression or pick up a set tsp 5.3 heads

 

I was at this point with my 4.8 before as well. The valves is a good idea. I was told go with the stage 2 5.3s but then again I was told those would put a 6.0 at about 10.5:1 comp...
this helped me a lot to understand what I needed to do for my 6.0. I was told I would need about a 58cc chamber for the 4.8 to be about 10.5:1
http://www.smokemup.com/tech/ls1.php

 

What is the max advisable milling for 4.8 heads? This is just temporary until I get my forged 370 going. I'm running a fairly stock setup with just intake and LT's. I want to bump the compression and port out some heads with a cam.