Higher amps mostly. Although the GM 10si alternators like this one are highly reliable and if needed, can be rebuilt for $20 in parts.

Gotcha, did you source from DB on eBay or elsewhere?

DB. Have had no issue with it.

In my opinion, the best alternator out there is made by Prestolite. I have installed dozens of these, and sold hundreds over the counter. They are 90A
and easily put out 50A plus at idle. They have been on the market for years, with a proven track record.

http://www.dbelectrical.com/p-12313-...FYiVfgodi-oCqg