I apologize if this has been answered. I did a search and didnt exactly find the answer im looking for.

What is the differences here? For my specific vehicle (1997 chev tahoe 5.7) there is the 270 XP and 270 SP, only difference i see is 10 amps at idle difference, with about a $50 difference in price. Can anyone clarify this for me please?

No need for an apology... In short, the SP is the largest Delco-Remy (GM) large case alternator we build on, the XP is a large case Denso alternator. The SP is old school tech with wire wound (loops of wire) stators, the XP is latest technology and uses hairpin winding. They both have REALLY similar outputs on paper, but hands down the XP is the better alternator. At industry standard ratings, they're within 10 amps at "idle" but on some vehicles that spread can be 60-70 amps as the SP drops off quick below idle, the XP carries it's output to sub-idle speeds. The XP also has 12 diode rectifiers, the SP's have 6.. For the money right now, by the XP's because they're going up at the end of the month, or off sale I should say..

In short, flip a coin as they are both better than ANY alternator you can buy in that output range, if your looking to save a little more coin, the 280 pro which is the little brother to the SP is still one mean little alternator, and at ~$400 is hands down the best alternator for the money on the market and is what we sell most of for the GM's, but it's like a 37, 35, 28 split (roughly) PRO->XP->SP..

Im working on a good explanation graphic to clear this confusion up so sorry about the confusion...

I understand what your saying.. when the time comes XP is more than likely what ill order. Problem I have is im going to be buying a new vehicle soon so buying right now isnt gonna work for me lol. Probably going to miss the lower prices im sure, but when I get my tahoe sold and find something else I want ill be hitting you guys up. Thanks for the response.

The XP is the alternator to get if your going to switch vehicles.. We can re-case it to fit just about anything whereas with any other alternator, your pretty much stuck with a *like* vehicle.. Either way, those 2 alts are flagship units and you cant go wrong with either one...