Can someone tell me what the name of this part is and a ballpark figure of how much it should cost me to get it replaced please?

It is a pipe across the back side of the motor from one head to the other and i think it connects to both the intake and exhaust.

I'm sorry to be vague but I am interested in buying this truck but have not seen it yet the seller is telling me on the phone it has a vacuum problem and this will fix it.

The truck is 75 miles away and I would really like to find out before I spend the time and money to go look at it.

Any help would be greatly appreciated.

 

The only tubes I can think of off the top of my head are

-EGR tube
-Tube that connects the heads from the rear/Head cross flow tube?

Any other tubes, I can't think of at the time...

 

that is the thermactor crossover tube. there is a diverter valve there that is vacum controled and costs about $85 by itself. if you want the truck take it to a certified mechanic and pay them the hours wage to check it out. and dont go to a shop the seller recommends just to keep it unbiased.