GM Alternator Part Numbers and Applications
This list is for some basic configurations, what they are used on by the connector clock position. Both Delco and Lester part numbers are listed. Most other brands use a P in front of the Lester application number. And if you haven't seen a pattern here the dash number on the end is the connector clock position (common 6.6" 180 degree mounts)
What is this clocking thing? It refers to the location of the connector in relation to the mount ears.
| 10SI Alternator (63 amp) | ||||
| 3:00 | Delco 1105360 / 321-39 / 7127-3 | 78 Chevy Camaro 350 with AC | ||
| 6:00 | 321-135 / 7127-6 | No application was found.(** See note below) | ||
| 9:00 | 321-41 / 7127-9 | 79 Buick Regal 4.9L (301W) with AC | ||
| 12:00 | 321-43 / 7127-12 | 77 Pontiac Grand Prix 5.7L (350R) with AC and HBL | ||
| 12SI Alternator (78 amp) | ||||
| # | Delco 1100250,1105370,1105372 / 7271, 7272, 7273 | 83 Chevy Cavalier 2.0L | ||
| 3:00 | 321-247 or 321-357 / 7278-3 | 85 Pontiac Firebird 5.0L (305H) no AC, HBL only. | ||
| 9:00 | 321-244 / 7278-9 | 85 Oldsmobile Cutlass Supreme 5.0L (307Y) | ||
| 12:00 | 321-249 or 321-254 / 7278-12 | ????? | ||
| 12SI Alternator (94 amp) | ||||
| 3:00 | Delco 1101308 / 321-266 / 7294-3 | 84 Chevy Camaro HiPo 5.0L (305G) 94amp | ||
| 9:00 | 321-269 / 7294-9 | 85 Buick Riviera 5.0L (307 engine) with HD options and AC | ||
| 12:00 | none / 7294-12 | NO AC DELCO part number or application | ||
| 15SI Alternator (105 amp) | ||||
| # | 7134 | 81/83 Chevy Camero 5.0L | ||
| 17SI Alternator (120 amp) | ||||
| # | 7287 | 86-90 Chev, GMC, P series van 6.2L | ||
| CS130 Alternator (100 / 105 amp) | ||||
| # | 7808 / 7888 | 88 Chevy Caprice 5.0L (4V) | ||
| CS144 Alternator (120 / 145 amp) | ||||
| # | 8112 | 93 Caddy RWD, 5.7L V8 | ||
NOTE 1 - No application was found. The 6:00 position would put the two wire harness connector in
direct interference with the main mounting bolt and so it is possible that no passenger cars
use SI series with 6:00 positioning.
NOTE 2 - If you need a one-wire alternator most of the brands have them available. AC Delco
has two types, the 10SI 72 amp is pn 321-349 with the connector at the 3 oclock position and a
15SI 105 amp unit is pn 321-667 with the connector at 12 oclock.
What are these Lester numbers? Lester is an automotive catalog service company. They do not make alternators but the Lester catalog system has been used as an application “cross-reference” for years and other companies, including AC-DELCO.