Likelihood of my Alt Handling a Heavy Load

Depends, you talking about a class D amp? Will probably be fine. Years ago when you were trying to get 1000+ watts out of a class A amp it really did pull a lot of current but your probably talking about maybe 60-70 amps of draw at peak. Most of the time will only be a fraction of that.

Just make sure to use the proper gauge wire and ground everything properly.

It all depends on the situation, man. What vehicle is it in? Personally, my Grand Prix's stock alt handled that kind of a load fine; but it's got a bigger stock alternator than most vehicles.

my gxp has a 145 amp in it, no idea where it came from but apparently it was from a truck of some sort. previous owner put it in. tested 140 though. Seems to stand up fine on shark 2k at 1 ohm with about a volt drop. Now to drop the saz 2500 in and see what happens.

op, have you done big three yet?

the big three is the one of the cheapest and easiest upgrades you can do. Ditch the cap its just going to strain the system more. And generally the voltage at your amp is about a volt less. so keep that in mind

Sell the cap and use the money from that to get a Big 3 kit. You won't regret it.

oh sorry lol the way you worded it sounded like the big three was pricey lol you dont need a alt to do big three.

My 90 amp alt couldn't keep up with less than 800 watts.

**** that *****, must be wiring. I've seen less do more.

No, it is a supplemental wiring of your power and ground between engine block, frame and alt. some vendors on here sell pre-cut kits, mylows10, and others can help you out.

pretty simple really -

your alternators job is just to keep the battery at a steady voltage, if your battery is weak then that alternator is already working overtime to keep it charged as is, then adding more of a load I/e and amp is of course going to create a voltage drop.

In a normal heathly system with proper gauge wiring and well done connections, having an occasional 60 amp draw over stock isn't going to hurt it. Considering on average most cars probably pull 20-30 amps stock, theres enough headroom to pull more, you really have to be pushing a system hard to be pushing beyond the charging limit.

I would say once you go beyond a simple sub amp + 4ch, and get to the point where your max current draw is over 100amps, it may be time to consider an alternator. Calling it a certain # of watts wouldn't be accurate enough, since wattage claims vs. current draw are vastly different.