Some MPI Manifold/Dodge Truck specific info:
You need one 3/8" barb for the PCV and one 3/8" barb for the brake booster. That leaves
4 ports remaining. If you have cruise control, you will also need a 1/4" barb for that.
(Which would leave 3 remaining ports.) To make ordering a kit as painless as possible,
if you do not specify a custom vacuum tree configuration, I will give
you the "standard configuration". This consists of two 3/8" barbs, one 1/4" barb,
three block-offs, and one 1/4" cap. This will allow you to hook up your
PCV and brake booster, as well as your cruise control, if you have it. If you do not
have cruise control, the 1/4" cap can be used to cap off the 1/4" barb.