GEMS P38 Alternator

Maximumwarp

Well-known member
Mar 22, 2015
836
26
Fairburn GA
I'm looking for the alternator upgrade to my 97 D1, which I believe is the 120 amp P38 Magnetti Marelli version. If a pulley swap is necessary for this, I'd need the correct pulley (my truck is sans-alternator currently). I also need the mounting bolts.
 
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robertf

Well-known member
Jan 22, 2006
4,780
354
-
Is there a physical difference in the p38 and disco alt? I bought a p38 120 amp from rock auto, alternator shop tested it at 100 amp.
 
Apr 20, 2004
6,926
223
Floyd, Virginia
They had a 100 and 120 aftermarket for the P38. Rock auto probably had it listed as what was supposed to be on there and then sold whatever the vendor had in stock. The majority of the time the 100 would work just fine on the p38... especially coil conversion trucks with less draw.

Bosch makes a 120 as well. It is 240.00 new and we use those from time to time.
 

CORover

Well-known member
Jun 11, 2007
745
65
Colorado, USA
Is there a physical difference in the p38 and disco alt? I bought a p38 120 amp from rock auto, alternator shop tested it at 100 amp.


Bosch P38 will not fit on the DI and vice versa. I tried that when mine died, I had a spare P38 one laying around, and then I realized I had one from a 98 4.6 GEMS RR I pulled. The GEMS RR bolts right on the DI pulley and all.