I would say you should look at the mechanics not the coil. Many wcs work fine with stock coil so your issue is not the coil but the mech. Sleeve, brackets, how it lines up, etc
There are a few ways to weaken a coil:
1) a bit of padding on the coil stop to give less throw
2) a resistor on the power lug. I wrote about this to weaken stern slings and used 25 watt 4 ohm resistors for those
3) swap with a weaker coil.