inlet manifold vac. take off

[peester]

hello
http://img.photobucket.com/albums/v11/peester/SP_A1677.jpg
ive taken the vacuum take-off valve thingy off my x14xe engine and its huuge. I think its an M14 thread!
Just wondered if anyone knows of a smaller one; not quite such a big thread..? m12, m10 thread maybe..? if so what model gm lump? etc

reason; i need to fit a vac. take-off to my dcoe inlet manifold.

thanks