Coil spring isolators for Daytona's, Shadow's, k-car's, etc ARE available in rubber from different places. BUT I have been asked to make them in polyurethane. Is this something YOU would buy?
I do make them for the Dodge Intrepid type cars (LH) (2nd gen) and they are
a little pricey. But the K-based car ones are simple compared to LH so
they shouldn't be more than the rubber ones sell for, although I still need to price them to see.
Here are the LH car ones I make.......
http://polybushings.com/pages/LHcushions.html
Let me know what you think!!
Johnny
PolyBushings.com