what are the for. to understand they are only for cable trans. would i need it to a b18 in EG with hdryo trans

I don't understand your specific question, it made no sense to me, but the intermediate shaft is the section of axle between the tranny & left(driver's side) half shaft.

i mean where does it bolt up to? do u have a pic? this guy is sellin em for 50 bux. on ht.com when people list parts that s needed for a sap, they NEVER SAY intermediate shaft. they say motor,trans,axles, linkage,ecu and motors

One end goes into the tranny and the other end receives the left shaft. It bolts to the block w/ 3 bolts. Now wether or not you need to swap them for your application or not I couldn't say. Did you throw this question at the swap nuts here?