I have just recently bought a rb2530 complete off another forum member with unknown specs. My issue is that I have just noticed that it is an a6 block and I just really want to know the best way of finding out weather it has been a forged Rb 30 intended for sohc and they have just slapped the 25 head on it or weather it is built for the higher cr for the 2530. I sorry I'm not very good at explaining what I'm trying to achive but besides paying for it to get pulled down and getting the compression ratio checked is there another way of finding out