Conversions & Hybrids - Alternator Capacity - adding heated seats

In my '68 cutlass LS1/4L60 I’m adding heated seats. I'm wondering if the alternator will keep up. I'm guessing it will, but here are the details. I'd appreciate input with more knowledge than I.

2002 pull-out from a WS6. I believe it’s a 105 Amp alternator. Does that sound right? Its stock.

Current electric consumption: Headlights, Cooling fans, 225 fuel pump & heater fan. That’s the extent that consumes much.

I'm adding 5 heated seats. Both front seats & three spots in back. Each can consume 5 amps on high. That totals new 25 amp draw.

I 'spose I could turn this stuff on and use an amp meter to find the loads but the electrical system is currently partially apart.


Opinions?

Fuel injection and O2 heaters have some surprisingly large fuses on them, definitely will draw more amps than the head lights.

I would be tempted to just hook everything up see what happens to the voltage at the dash when everything is on (cold engine, heater, lights, all seats, stereo at full volume etc.) If you can't maintain close to 14 volts at the fuse box then just upgrade to a larger alternator then. The higher capacity alternators are the same physical size so shouldn't be tough to leave the fuse out of the seat heater circuit until you get a bigger one. I think you can even get upgrade kits that allow rebuilding the current alternator to more amps.