my1979impala

I purchased a wilwood tandem master cylinder for my 79 impala. The MC looks like it should be mounted rather flat since it has shallow bowels front and rear, however, the way it mounts in the car sits it at a roughly 14 degree angle. This means when i fill it up the fluid runs from the front chamber to the rear through the little hole (equalizer hole?) and the rear ends up full and the front empty. I talked to a guy at wilwood and he said to plug the hole with a screw wrapped with Teflon tape. That seems a little rigged to me so I was wondering if anyone has any other advice. Ive searched here and google for a while but I seem to be using the wrong key words.

Just to be clear, this will not have any pressure on it. Im just trying to plug the hole between the two chambers to keep the fluid bowels separate.

I thought of JB weld but have seen mixed results about it working great with brake fluid or turning to putty and falling off. There were also mentions of marine tex but no one really seemed to follow up saying it worked or the fluid ate it away. The last one i saw was a guy saying to melt a zip tie to plug a hole in a clutch master. Does anyone know if this would work on a brake master? or would the brake fluid eat the plastic? any other plastics that could be melted and put in there?

my1979impala

after thinking about the melting a zip tie thing im wondering if i could just cut up a soda can (clean it off really good first) then melt that and pour it in the hole. anyone see any issues with this?