That's on my 2 do list for my 1984 and 1984, too. My intended solution is this:

Use 1/2 inch copper pipe. Take an old nipple, the one that holds the flame trap and hoses, use it, with the cup cut off, to coupling the pipe to the nipple on the top of the breather box. The top of the pipe should be just above the intake runners. But, be ready to trim it as needed.

The newer style rubber cup will slip tightly onto the top end of the pipe. Put in the new flame trap, use the new style holder. You will need the new style larger hose, too.

Since I have not yet done this upgrade, there may be glitches unknown to me. But I hope this helps, with a minimum of confusion.

Bob

:>)