The flywheel bolts directly to the crankshaft. There is no shim or spacer on either side of the flywheel, and generally one should not be used at all. The only time you would ever consider running one is if you have machined a significant amount off of the flywheel and are trying to space it out to correct that issue, however on the R154 flywheel this is not a concern as it is a pull-type release bearing and if you ever get to the point where a spacer would be considered you've likely taken too much off and the clutch will likely not release anyway.
td;dr: No, do not put anything between the flywheel and the crankshaft.
Jeff