What plug do i need for 73 slant six and what is total timing on a slant six.Also
what would resistance coil would i use with a orange ecu and ballast resistor.Someone has converted it from points to electronic want to make sure they changed coil if needed.Looks like original coil.Thanks

The answer to your question about timing over here is the same as it was over there. Spark plugs: use NGK № ZFR5N (stock № 3459), with the metal ring washers removed before you install them.

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The engine had n14y champions in it when i got it.I found a old chiltons book and it says to use n14y plugs .I bought a set of the ngk plugs you suggested and they are are longer than the n14y plugs.Will this be a problem if i put them in.Thanks for your reply

Only if the slant had been milled for 10:1 compression or more... on a stock motor they fit fine.