Hey fam just finished dropping the 455 in my 79 cutlass. I can't remember if I pulled a 307 or 350 out of it . But question is this, money is low so I haven't bought a new altenator yet . But I have the one that came off the other engine , can I use it since it was already in the charging system of my 79 . Or is there something about a bigger engine needs a bigger altenator? 🤔 only new accessories that will be getting added for now is tach. Water and oil gauges all else will be the same . So shouldn't the old altenator work for now ?

 

Look around on the alternator and see if you see any codes/numbers or other markings. Also check the case & fan to see if it’s a 10SI or 12SI to narrow down what the output is. Unless you have a bunch of aftermarket accessories, you should be fine with something between 65 and 95 amps alternator.

If you’re using HEI, be sure (i.e. check at the distributor) that it’s getting a full 12v when switched on.

Until you find that the battery does not have 12v, your alternator is probably fine.

Chris

 

Your alternator should be fine. You don't plan on installing a CB or subwoofer, do you?

 

Yes, you can reuse the old alternator. Engine size does not dictate the size of the alternator, electrical load does.

 

Thanks family .