Hi Al,
I found this setup works well for my '70 b20 with a weber:

I got a small breather element from pepboys, the kind they sell for the rice-boys, and stuck that on the oil trap. Then ran a hose from the top of the oil filler cap to the oriface on the manifold, and blocked off the oriface in the air cleaner with aluminum duct tape.
This reversed the direction of the crancase air flow, like on the b18s.
The problem with the oil traps is that they dont.
(trap oil that is)
So I was sucking a lot of oil into my manifold and spewing a lot of black smoke when decelerating at freeway speeds.
The other advantage is that since the breather element was marketed for for the fast-and-the-Furios types, you can get them in red so they match the engine block :)

Most of the manifolds I've seen have a port or 2 right under the carb with all kinds of iteresting bits of plumbing stuck in them, so if your comfortable with drilling & tapping one, that should work allright.

Dave-


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'70 145, Webber converson, pretty much stock other than that. & 89 740Turbo Sedan