Just to answer the question, the few tenths of an ohm resistance over will not be noticeable unless you are in a seriously cold climate. Resistance decreases with heat and increases when cold. Having your coils mounted in the head like our bikes will (new bikes use them in the head) heat them up significantly decreasing resistance for example, 1.5 ohms cold tested to 1.2 maybe even 1.0 after heated up from running. You do not want to go lower than factory 1.8 ohms or you will risk overcurrent damage to ignition electronics. All that said, I see it as not necessary to spend the extra money buying 4 resistors and wiring them in parallel pairs from the factory ignition wiring when you can wire in series and have the resistance match up well.