Stock is 155 - 170 psi per the service manual. That would be for the stock compression ratio of 9.6. I'm assuming you are probably running something lower than that with your big SC which would lower your psi reading, so your number seems like it is probably pretty reasonable to me. Perhaps someone with a similar setup has some numbers to compare against. Usually variation from cylinder to cylinder is the main thing to look for and your 2-3PSI sounds very tight to me.