Like I said, I couldn't find a link to the exact motor mount you posted, only the one made by FG. If the one you posted can take a 1/5 scale 58mm diameter motor then there's no reason not to consider it.
Either way your truck is heavy, over 20lbs. Anything less than a 58mm diameter by 90mm long motor is going to be struggling to push that much weight and heat up too much unless geared for a low top speed. The big 5890's have the torque and power to push that much weight and not heat up. As far as brands I'd stick to Castle or Leopard, they're the proven performers in 1/5 and 1/6 scale vehicles.
Sorry but but I can't really help you what voltage and kv to run. Your vehicle is on the lighter end of the big boys and I've seen some people run 6s in similar vehicles. If it was me I'd go 8s, that's what should be in there and then you know you'll have all the power you'll need. But I also like lots of power. Either way you need to go with a 1/5 esc and they're all 8s capable so it's there if you want it. Again I'd stick with Castle or the new Hobbywing Maxx5 which has much better support than any Turnigy, Toro or other Hobbyking brand.
If you provided me with the exact tooth count of all the gears in the drivetrain as well as the tire diameter and voltage you want to run I could do some gearing calculations to help figure out what Kv to run and gearing. But I need to know all those things.
Last edited by Maj_Overdrive; 04-13-2016 at 10:10 AM.