[Prowbar]

The canister filter on my 305E never came with the spring. The filter centers on the center bolt and seals using the cork gaskets. Torquing down the bolt should compress the filter somewhat.

The bolt is sealed by a o-ring on the bottom, it should not leak when the bolt is loose and this way the filter can be filled with oil to prime the filter.

You could start without priming but I would recommend disconnecting the coil wire to the distributor to prevent start-up until you get oil pressure.

Don't forget to fish out the old gasket out of the oil filter adapter on the block.

Good luck!