Will a KA24de from an Altima work as a swap in an s12

No.

Altima is FWD.

Even if it's on a RWD transmision

The block is the same, but dont screw with it. Just pick up a 240 engine, its easier and cheap.

Sometimes the blocks *aren't* the same, dude to mounting reasons. But often times, the manifolds are different, and intakes would point directly into the firewall of a RWD chassis (assuming they fit in the bay).

Blocks, head, dizzy, vaginas, are different from FWD to RWD KA blocks

Oil pan, etc., the list goes on.

More often than not you can use a FWD block in a RWD car, but you have to get new everything.

i you use the Altima engine i think the distributor will end up trought the firewall

Frank @ spoolsport.com

do you really want an engine from mexico anyway? exactly

front covers differ as well as Water pump placement. head is different too.