I think I blew a piston on my 87 GN.(will know for sure soon) I have 150lbs of compression in 5 cylinders and 0 in one. also.oil is spraying out of the dipstick tube indicating crankcase pressure. What would you guys recommend I do? Replace the one piston,rebuild the whole motor,or buy a new short block/long block? Thanks in advance for your help, Tommy