So you have a line on a little M block at a good price eh....
Well, that block would slow your car down at least 6 tenths, and you wouldnt be able to qualify anywhere in the country.... Therefore, I think you need to give me the contact information for the block, so that I can purchase it at once, just to save any other racer the grief of having it ruin their combo
Seriously, I wouldnt think the extra 20 lbs would even be noticed, and from what I have heard about the M stiffness, it may make more HP and be quicker overall...