I'm actually doing the same thing. I converted Nitro TC3 to electric, then did my HPI Firestrom 10t, waiting on the battery trays to finish converting my Savage 25 and the next 1 will be my Savage XL conversion. Not sure what Savage u have. I did all Spektrum ESC's and Motors in my conversions. I'm out of town right now for Thanksgiving but when I get back I can post some pics.
I would say first thing, 8s is way to much power. U will snap drive shafts and probably break diffs since the electric has way more power than nitro. I have and will be doing just 6s. Can always gear it different also to help. U can try 8s but u might be wasting your money if u have buy a 6s setup if it doesn't work. I was gonna do 8s in the Savage XL but after researching is why I read 8s is to powerful.
Which Savage are u converting?