Equal length leads isn't *really* important if you have good leads. If you have poor leads (the stock ones are terrible...) you get huge amounts of difference in spark strength because you have massive differences between different high resistance leads. It does make a difference. Increased resistance means less voltage at the spark plug which means a weaker, and shorter spark. Sure for a stocker, its not going to be a problem, but at high boost/high rpm, beyond what the motor was ever designed to handle, and beyond what the ignition system was ever meant to deal with - positive spark is important.
I still am iffy about running 8ms on stock coils... by that logic i should be able to run a third as much again on my big bosch units - but i've spoken to guys who race 1000hp rotaries on the same coils i've got and they say they are lucky to get 1 run in on 4.5ms without at least one of them blowing out.
Personally, i'd stay away from the stock mazda coils - i have killed them on my motor, bolt stock and NA - even before i put the microtech on it and started mucking around with dwell. With direct contact to the engine, and an engine cover ontop, they don't get much chance to dissipate heat. For mine, thats their biggest weakness.
I still am iffy about running 8ms on stock coils... by that logic i should be able to run a third as much again on my big bosch units - but i've spoken to guys who race 1000hp rotaries on the same coils i've got and they say they are lucky to get 1 run in on 4.5ms without at least one of them blowing out.
Personally, i'd stay away from the stock mazda coils - i have killed them on my motor, bolt stock and NA - even before i put the microtech on it and started mucking around with dwell. With direct contact to the engine, and an engine cover ontop, they don't get much chance to dissipate heat. For mine, thats their biggest weakness.