Need serious Vacuum Diagram assistance.

[WDGS]

I have a '74 with EGR - stock 302 and 2100 carb.

For now, Im keeping the EGR. I bought the project in pieces so the vacuum stuff was all messed up/half removed already.

I have two ported vacuum switches - one on the mainfold heater elbow (2 ports) and a 3 port one on the thermostat. I have also gone to a single port vacuum modulator

I have found 2 relevant diagrams. I just dont know which one to use.

1) ' 73 Emissions Vacuum diagram.

http://classicbroncos.com/forums/showthread.php?t=152862

However if I go by this one:
A) I dont have a spark delay valve, would i need one?
B) I assume I just eliminate the loop to the trans modulator.

2) Vaccuum Diagram

http://www.broncohio.com/tech/national.jpg

However, if I go by this one:
A)This one has three Ported Vacuum switches. What I do about that
B)Vacuum solenoid?? Is this the carcoal canister thing?
C)Exhaust heat control valve?
D)Items 14, 15 and 16. Thermactor stuff. What is this stuff?


Help would be very much appreciated - I am moments from firing my restro up for the first time.

 

[Viperwolf1]

Are you looking for 100% originality or just basic functionality?

Look at all the diagrams here: http://www.mustangbarn.com/73vacuum.html You can see that the EGR just needs one ported vac switch to function. The modulator would have originally been a dual port but would have affected the shift timing and not EGR operation itself. You can keep your single port modulator plumbed to manifold vac.

The distributor uses the 3-port vac switch with a 2-port vac adv can. The '75 diagram doesn't show a delay valve.

Here is some info I found recently about original emissions equipment.

 

[Rustytruck]

Do you know if the was origionally a California Bronco?
in 1974 there was 2 Bronco 302 motors. A california specific and a 49 state motor. the 1974 California specific motor had factory installed Duraspark ignition,dual port vacuum canister, smog pump, gulp-valve for the smog pump, injected air tubes in to the cylinder heads, a vacuum amplifier mounted on the back of the intake, egr valve, (2) ported water heated vacuum switches, Exhaust heat control valve which was mounted under the drivers side exhaust manifold. It is a thermostated counter weighted exhaust butterfly valve which blocks the exhaust flow on the drivers side exhaust pipe to warm the engine quicker. and a 2 port vacuum modulator for automatic transmisson and of course the vacuum controlled air cleaner assembly and charcoal assembly.

The real question is do you have a factory Duraspark ignition motor or did you engine come with points ignition.

After 1974 all Broncos got the duraspark ignitions