Where can I look for performance data from amplifiers?

Hi guys, I read through the forum yesterday and the eyes were opened: I’d rather separate myself from my 30 kg HUT tray and rebuild in my car now. And there are some questions there when planning and I want to open some threads and hope for your help. This thread here is one of them I have to expand my analge as in the overview. in this context you can also quietly tell me what you think about it. I ch jetz has an amplifier from Kenwood. Model: KAC-848. I don’t know exactly how much power he brings with how much ohms etc. and I would like to do that. Where can I look up something like that? Because if he has enough power, then I would also let the rear boxes run over the amplifier. (on the schematic in the attachment they run over ́s radio). is he sold no more else can I look there… does someone know? Thanks. Propp