Most of the time the spacers/nuts that go between the strut top and coilover spring hat have to be custom made. $50 is a resonable fee to sort this out.
The best setups have either the spacer or spring tophat located on the shocks 2 flat bits near the thread. This way you can hold onto something when you do the shock nut up. I have developled a spacer that locates in the shock, and has flats ground onto it for a spanner. This way you can use 2 spanners and do the shock nut up as tight as you like. No need for a rattle gun.
