block guards wont make your sleeves stronger neccessarily because they only stabilize one pressure point.... they only stabilize the top which isnt really the part you need to worry about... the sleeves in the B20 are just straight weak and ive heard of the crackin under boost as low as 7 psi with rods and pistons... now that may have been an isolated event but why run that risk and have to spend the money all over again??? youd be better off spending the money once and do it right... go see Collin at Racing Integration or John at Secret Services and one of them will lead you in the right direction and help u get the ball rollin.... I personally think that the Golden Eagle sleeves are pretty good as well as Dartons.... and then get a nice set of Eagle Hbeams or crower rods which are basically the same, and some wiseco/endyn rollerwave or JE 9.0:1s and the block will handle all the abuse you can throw at it..... But take this information as a suggestion and talk to a real professional and see what they think... I personally wouldnt boost on a stock B20 bottom end because youre still gonna have to spend the money after it goes boom... build it right and boost away and youll be very happy you did so.....