My question is, how do you get an IAT sensor, a big brake booster vac line, and another vacuum boss for the heater controls, all into the single 1/2" NPT hole on the top of the intake manifold?

 

Know where you are coming from but my Accufab 4bbl TB has 3 ports at rear that take care of vac requirements

I was going to put the IAT in the air cleaner base ( like the relocation kits ) leaving intake hole free for brake.

Worst case, will drill and tap a new 3/8" hole in the vertical face of rear drv side runner for IAT

 

Well thats good to know that the throttle body I buy will most likely have some vacuum ports. I would be a little concerned about getting an accurate temperature reading if it was mounted on a T or outside of the throttle body.

 

Im using an edel 4bbl TB with vacuum ports on mine. The TB handles the heater, MAP, FPR, and PCV, with the runner port doing the brake booster.

As far as teh IAT, you could get one of teh later model press-in plastic ones that mount in a grommet. You can then just put a grommet in the air cleaner, and install the IAT there. The IAT I used was from an '00 vortec truck, and the grommet, IIRC, was for a ford ranger PCV fitting. I think pretty much all late model GMs use this type, so its pretty common. The thermistor in it has the same response curve as the early IATs and CTS's

 

I run a custom 90 deg elbow with 5 ports for vacuum functions. Setup with LS1 throttlebody.

If you do the MPFI type TB's then hopefully they have enough vacuum ports. You can T into some of the ports like fuel regulator and booster in one line, to save space. IAT like others said, relocate. I am using a stock one threaded into that manifold hole but thinking about relocating it. I got alot of things running on vacuum on this motor so having alot of ports on the elbow or throttle body help

 

Well since I can relocate the IAT to the air intake ductwork, and the throttle body will have a couple vac ports, I should be good to go.

I'll run a T off the TB. One side to the heater controls and vac tank (which needs to be kept for proper operation of the heater controls right?), and the other side of the T to the FPR. Brake booster will go on the intake runner port.

I'm not quite sure how the charcoal canister functions work without having it in front of me right now, but the vent one prolly needs its own port in the TB. the line going to the purge(?) solenoid can prolly be Teed into the FP vac line somewhere. Can someone clear up how that thing-a-ma-jig works???

 

Early TPI had the canister purge line going with the PCV into the intake ; later use a port on pass side of the TB
Vette setup shown

 

Thanks for the diagram vetteoz.

I don't recognize the tank pressure control valve. IIRC, there are 3 lines and an electrical connection up there. 1 line to the fuel tank, 2 go to various places on the intake.

In your diagrams it shows that the two lines do go to different ports, so as I assumed earlier, one is vacuum source (to operate the solenoid??), and the other is the actual vapor vent hose. So the vent should have its very own port on the TB. The other line can be on the same "circuit" as the FP reg.

 

On the Vette system as shown , vac from the port under TB controls the tank pressure valve.
Purge solenoid is electrically operated by the ECM

Not as such .
As shown on the 85 -86 setup ,the canister purge went into intake with PCV gases so with a SP intake, purge line could go to any vac port, even one on the intake

 

Yes, but the PCV is a "contaminated" line so to speak, as is the vapor vent line.

 

Im going with an genIII TB with a elbow on my super vic. So I decided to run a port vacuum block. Has 5 1/4" npt ports and a 3/8" npt port on each end.