Why not buy a vaccum T and on the passenger in the bottom of the intake cut the hose and splice in there for a good vaccum source. I just did this very same thing a hour and half ago for 1 of my cars and have done it at least 4 other times on my other cars. I got the idea from Nick McCale it was his idea and works quite well it is very inexpensive the T is about $3 and you just need a little extra hose that's all so under $10 problem solved