what is the difference between a series 1 and a series two ignition coil? I'm thinking the plugs may be different or is one better than the other?

in short the s1 is the same as EF the s2 has higher output and uses a 1.3mm plug gap. the lead ends are different and the 4 pin plug is different.

Thanks guys.

One more question. Is the wiring in the looms the same so that I could change over the plugs?