It says lipo with regulator so it probably doesn't take 8V.
I had used a 2S lipo without a regulator on my predator maxx and race revo which uses the 3PM rx and Hitec 5955TG servo. All the components are still working though they don't get as much attention compared to my flashlights .
Castle Neu 1520 on 6S LiPo Powered Gmaxx (Nitro Killer)
Predator with OS .21TM
Supermaxx with Mach .26
Revo with OS .18TZ
Kyosho ST-RR Conversion
Ofna CR with Tekin ESC/Motor (2)