I'd take the UDP off personally. (Very long story read up if you are interested)
Find another mechanic.
...and TB spacers add zero power. (dyno proven countless times)
It's old school thinking to believe a TB spacer would work like a carb spacer. The design of the "dry" manifolds now days is so much supperior to intake velocity and proper cylinder filling.
Adding a spacer between the TB and UIM does nothing but make you fabricate more parts to make it work. Nothing else.
