Ive been looking at other old 89' dodges with 360s they have a hose from underneath the air cleaner going to I guess an air heater mounted on the drivers side manifold. Looking at my 89' with a 318 mine doesnt have that. Did 318's come with that?

 

i have never seen one.

 

Yes, the 318 in my 83 has one. Of course the hose is missing these days, but yes it was there at one point.

 

That is to draw heated to the intake for better driveability on a cold start.
Should be a temperature controlled vacuum switch that allows vacuum to open a valve in the air cleaner to open and allow cool air when it is warmed up.

 

I dont have the hose or the heater.My truck is a 86 w/a 318

 

The air preheater on the manifold usually rusts and gets discarded.
I still have it on my 87 D100 and 5th ave.

 

So I just leave that opening alone??

 

Yes. Won't hurt any thing.
If it runs ok on a cold start and while the motor is warming up it not needed.

 

All it does is help the driveability while the engine is cold.
Just leave it open.

 

My 89 with a 318 doesn't have one.