New air compressor or rebuilt

[al b]

1 )The guy at the auto parts store is trying to talk me into a rebuilt air compressor . He says they put steel sleeves in them and they will last will last longer. I was told (by this sight the R4 units were junk the first time around and to stay away from rebuilt ones ) What do you guys think ?

2) Advance Auto is the cheapest on the rebuilt units around here but everytime they put in the computer it comes up the wrong one . (1985 300SD) When they enter it in the computer as a 300D it comes up the right one . Are the holes the same in the r4 compressor for the two cars or should I just get a new one off the internet ?