Been messing with my 2002 cavy 2.2 ecotec for a LONG time. Timing grenades in my car. Went to junk yard used a block with crank, pistons, and balance shafts. Used head and cams from my cavy. Are the balance shafts specific to the crank and cams or just crank or just cam? Or will the mismatch be minute? Ready to give up if someone wants to buy it.