What about the replacement alternator doesn't allow it to fit? I'm assuming it is an SI alternator, and probably a 10-SI, at least according to this: http://bob_skelly.home.comcast.net/~bob_skelly/alternator_conversion/wiring_alternator1.html There shouldn't be too many versions of the 10-SI alternators for early Chevy small blocks. The only significant difference I can think of the clocking of the case. (3 o'clock mounting ears, 6 o'clock, etc.) If your old alternator brackets work I would stick with them. Unfortunately when you go to your friendly neighborhood parts store the person behind the counter typically has very little parts knowledge. I would take the alternator back to the parts store you bought it from and insist they give you an EXACT replacement of the one you had. Make them look in the paper catalog. Tell them you want to see the listing in the paper catalog. The average parts jockey wants to be an order taker - make them do their job and get you the correct part. (Yes this is a pet peeve of mine.) Also look at the part numbers on RockAuto.com , that may help you get the correct part number. Good luck. On Wed, Nov 3, 2010 at 7:25 PM, Saul Marsh <saulmarsh72@xxxxxxxxx> wrote: > Hi guys, > > I occasionally spend a few minutes when available trying to get my > alternator problem figured out. Brought my alternator to Autozone last > month and it tested bad, so I turned it in and got a new one. Thought I > compared the old and new one together, but apparently did not do a good > enough job checking it. Replacing an alternator should be an easy job, > right? New one doesn't fit. I'm having a helluva time and my car can't be > moved as a result. I wish I could get my old alternator back, just long > enough to move the car into the garage. > > My questions: > > 1. Do I have an alternator or a generator? My dash light says "GEN" and my > '73 GMC Sprint manual calls it a "Delcotron Generator Assembly." The > Autozone computer calls it an "alternator." > 2. Shouldn't there be a difference between alternators on pre-'75 and > post-'75 models? I bought shiny new chrome alternator brackets thinking > that the old brackets looked like something thrown together by some > shadetree mechanic. The new brackets are good for models up through 1975. > The Autozone computer shows the same alternator for a '73 307, '73 350, and > a '77 350. Maybe they tried to make one alternator interchangeable with too > many others. > 3. Where can I find some sort of identifying code on my engine? Given that > the previous owner used this Sprint as a parts car for other cars, I'm not > even sure I have the original 350 anymore. > 4. Am I an idiot for even taking this project on? > > Thanks all for your help. Nothing urgent here, but I sure would like to at > least be able to move my Sprint without selling it as a parts car. > > Saul > '73 GMC Sprint > Rules: Please play nicely with others. -List members page (text & pic links): http://www.myelcamino.net/eclist.htm -List members page (all pics): http://www.myelcamino.net/ec_list.htm