The free length of the springs is irrelevant. Fitted load, fitted
length and such are more important. With a coil over suspension
like the Spit's front that isn't perfectly perpendicular to the road
there is geometry involved in figuring out what sort of change to
the spring is needed to get the desired change in ride height.
I sort of remember working this out a decade or so ago when I
was actively developing the Killer Spit.
But given that you are talking about a 40 percent reduction in
front end weight, I'm assuming that you are pulling out the motor
and transmission and will be pushing the Spitfire wherever you go,
so ride height and handling is not really a factor.
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