i could nt tell you what size. need to take your apart measure it and move to the next size up. but i will look and see what i have on one of mine just for a comparison. the size is different for different carbs. air bleeds affect it cam, emissions.
on the pcv valve i dont know how the factory decide which one to use but they are specific to model and manufacture. but even then the differences are small. its basically a sized air leak. so i would think that one for a slant would leak less air then a v8 but this is a guess on my part