This is not an attempt to advertise, but this subject is coming up every couple months, and I would like to point out that the design and engineering work to make exact, molded, polyurethane suspension bushings, with stainless steel center sleeves, has been done and awaits funding for production.
viewtopic.php?f=34&t=2157Four front upper bushings.
Four front lower bushings.
Redesigned front lower fulcrum assembly.
Four rear lower bushings.
A cost estimate based on 3-4 year old materials cost puts the retail price at around $850 USD.
For comparison, one of the little classic car shops in Japan offers to replace the bushings in the customer's control arms for 20,000 Yen per control arm. That is new-old-stock, bushings that have been sitting on the shelf for 40 years, includes installation, and you must also pay to ship your control arms to their shop for installation, and back to you for delivery. I think that adds up to $1,434 before the shipping, and I doubt it would cost less than another $250+ for shipping back and forth.
RE: Lathe turning/cutting bushings
I investigated this prior to doing molded bushings.
Cutting polyurethane with a lathe is extremely difficult. The material is soft. It yields away from the cutting tool. Even 85-90 durometer material is "soft" compared to a nice piece of steel or wood. The labor cost alone for cutting each bushing was going to be more than twice the cost of the molded bushing. The material cost was going to be higher too, because of the money spent on all the material to be cut away in the making of each bushing. And, most importantly, the soft material would not cut consistently and accurately enough to result in a fit that would be accurate enough to be safely used on the suspension of an automobile.
If you have a pile of free polyurethane round stock and hundreds of hours of spare time with nothing else productive to do, then it might be a viable route.
However, if lathe cutting is the only option, I suggest delrin or hard plastic that can actually be cut on a lathe, and do not plan on using the car for passenger travel or pleasure driving due to the harsh ride quality.
