Hi, I've got a 91 civic si burning some oil and low compression in two adjacent cylinders. (No noticeable coolant in oil) 1) What's the likelyhood of a blown head gasket causing my problems? 2) Is it necessary to remove the cam shafts to pull the head off if I can see all the head bolts without any interferences? 3) After setting TDC on #1 cylinder and marking the belt and sprocket are there any worries with the belt slipping on the flywheel when the tension is removed from the belt? 4) If I find that the cylinders/pistons/rings are bad on the si, can I use the block from the D15B1 with the full head assembly intake, MPFI, and tranny from the si to restore to my original set up?