i have a 79 1/2 ton 4x4 ,351 modified ,bored 30 over stock,rv cam, edalbrock intake, holley 4160 600cfm carb. every thing else is stock, with c6 transmition has about 7000 miles sense the rebuild.here is when the dumb takes over. on the vaccum lines, one line goes from the intake manifold to the brake booster, the line going to the transmision vaccum modulator, does it come from the carb or the intake? and the pcv valve, can it be pluged in to a vaccum port on the carb or does it have to be hooked to the breather.(no stock breather,now has 10 inch aftermarket with k&n filter, i just bought the truck.also what would the correct ignition timing be for this set up.

 

Welcome to FTE!!! That is not a dumb question man. We've all been there. The only line that should attach to the metering block on the passenger side front is the vacuum advance for the carb. The ports on the bottom of your carb act just like the ports on your manifold. It doesn't matter which ones you use for power brakes or you trans. They are all the same.

 

thanks a bunch ratsmoker, your a big help bro. on the advance you said to atatch it to the passenger side front of the carb. would that be the top port or the one on the bottom. mine is showing two opptions.

 

The top port. It should be right behind the fuel bowl.

 

for distributor use port that shows no vacuum with idle; but increases vacuum with engine speed.

 

shane74

The brake booster and the transmission need constant, full vacuum.

The PCV plugs to the carburetor, also full constant vacuum. On the 4160, that port should be facing out on the passenger side, at the rear, bottom of the carburetor. Rearward and down from the choke.

And yes the vacuum advance needs what called part throttle vacuum. Which like said above, comes from a port on the carburetor that is above the throttle plates.