I installed a set of these cast aluminum valve covers this week. The oil cap on the driver side now is a push in instead of the twist on. However I can't find one that fits with a tight seal. The whole is a 1 1/4" but two different caps both fit with some play once they are pushed in place. They were both Spectra brand caps. I'm thinking that not having a tight seal will affect the PCV valve operation as well as eventually create some blow by mess. So far with only a few miles on the engine since installing them I see no mess or running problem.

Any body installed these and run into/solve this problem.
Summit part Pro-141-130 covers. they recommend a breather/cap but that won't work on the PCV side.
GW