Welcome to PF

1st thing. yu need a new block :P and they aint cheap at the moment as your 4x4 would have had the 200 block.. the 205 blocks not as strong but still good power gains if your not wanting to go mental on the power side of things. get it stripped then find out what piston sizes you have! might have been over bored before 0.25 ect. same for the crank..that way at least you know where to start from.. come on get the spanners out and start taking it apart plenty of people here to help out