I have a 1965 inline 6 260 engine that has been running a little rough. Spark plug 2 continually fouls. Plug 1 has 105-110 psi, 2 = 115-125 psi, 3 = 110 psi, 4 = 125 psi, 5= 115 psi, and 6 = 110 psi. I thought it might be that either oil was leaking around the piston rings or that one of the valves may be dirty and is not closing all the way but since #2 has higher compression than most doesn't that suggest against that? Car does not smoke or burn oil. Please help. Any solutions or tips on how high the compression should be are welcome. Thanks