s13redtop sr20det

My brother was looking into getting a 240sx with one of these engine in it... He asked if I would post on here asking about it first though...

How reliable are these engines? Any problems with them?

How much would it cost to rebuild if the need came?

Also do you think a 1991 240sx with this engine in it is worth 6k? I haven't seen it but my brother said it was primered, with a few small dings...

Thanks