Hey there, guys!

I currently own 2 Ibanez guitars. An Ibanez RG370DX and an Ibanez S520EX. The RG-Series has 3 pickups (an INF3, an INFS3 and an INF4) while the S-Series has 2. (An INF1 and an INF2)

Could anyone give some more information on these pickups, e.g. which ones have a higher output. The RG's pickups sound a bit more hot, so I was thinking about putting them into the S-Series (My main guitar). Is this worth the trouble, or are the pickups similar?

I don't have the money for active pickups at the moment, but I want a little bit of a hotter tone from my S-Series.

Thanks in advance.
From what I've heard and read all over the internet the INF1 and 2 pickups are considered the "better" pickups than the INF3 and 4, but you're ears will ultimately tell which ones are better for you.
Personally I think changing pickups in most cases is overrated. Especially in your case why would you like to have both guitars sound similar? I like my guitars to have different sounds and personalities. But that's just me, you can ignore this paragraph if you disagree.
But if you do change pickups I'd recommend you to upgrade a little more. The INF pickups by Ibanez are installed in the lower end Ibanez guitars which basically means they are not bad but not quite that good. You're not gonna find them in the so called "Prestige-Series" by Ibanez. Many of the "Prestige" guitars come with DiMarzio pickups like the Tone Zone, Air Norton or the Ibanez V7 or V8 pickups. Most of these tend to be a little warmer, fatter, less noisy than the INFs imo, or simply "better", but again your ears need to judge.
You can get a good DiMarzio Humbucker for 70-80 bucks and can't really go wrong with them.
It may depend on the guitar they're on. I've had INF3 and INF4 pickups that I thought were sort of nasty on one guitar; they came off and were replaced by something else. A while later, I was building a guitar specifically to test different kinds of pickups and see if I could get a set of notes that would tell me something about what did what. I tossed those iNF3 and INF4 pickups on it after they'd languished in the parts bin a while, and whaddya know, they actually sounded really good on that guitar. *headscratch*
I've had several Ibanez guitars with Infinity pickups. Inevitably they always get switched out for something better. To me they just always sounded muddy and dull. The majority of Ibanez guitars are a basswood body, and maybe these pickups would sound better in something like alder, but I've only ever heard them in basswood and they always have to go. I usually end up putting full fledged DiMarzio pickups in or in some cases Seymour Duncans. I've also done a fair bit with Lace Sensors and Bill and Becky pups. Everyone of them has been a major improvement over the stock pickups.
Yeah the RG ones are really hot... lots of output... but the problem is it's of the wrong and unfocused kind in my opinion.
Like poppameth above, I think they just sound like a muddy and dull mess.

If you want to swap pups, just save up money for something like DiMarzios or Duncans. You could probably score something used for a fairly low price.
Things with strings:
Ibanez J.Custom, Prestiges, RG8, SR5 bass etc
LP's, Strat, Tele
ENGL Retro Tube 50
5150 III 50W
Orange Terror Bass