As I get ready to hang the new exhaust and intake manifolds on my '78 300, I am thinking about post-emissions vacuum lines. I have the port on top of my tank and want to keep the line to the carbon canister to prevent fume smells. I know I need ported vacuum to the distributor. I think I will need to keep the PCV and cap breather lines to the air cleaner, letting air suction down the throat pull in any fumes from the PCV rather than (as I recall) manifold vacuum to the EGR. So I would only need a single manifold vacuum line to the carbon canister and cap off all the non-gas-tank ports on top? (I am ignoring the manifold vacuum lines to the brakes and trannie, they stay.)

 

as far as i know, cap it all with the exception of...
distributer advance
pcv
bowl vent(carbon canister going to front of carb)
heater controls to cab
brake booster

you dont have to run an egr but its a little helpful on the fuel economy, if operating correctly

i have only those lines that are needed for normal operation, everything else is capped and the egr is plated off.

 

Same here on my 81 F100 with 300 six
Dave ----

 

Need to check on the new carb to see if it has the port for the carbon canister. No EGR, I am installing new intake and 4 barrel. - just trying to see how I can keep the carbon canister hooked up. Forgot the line to the AC controls.

 

theres isnt s specific port from the carb to the carbon canister but on most carburators (idk about 4 bbls) there is a bowl vent, you can vent it to the atmosphere with a filter on the end.
a 4 bbl intake and carb will be easy for yah, eliminate the carbon canister if you can, it makes everything a little more simple. i took mine out and re-reouted everything to account for its absence.