RE: brushless 8ight t
As mentioned, if you stick with a 36mm motor (which isn't a bad thing), you need one that's longer, preferably about 74-75mm, but at least 65mm. Larger motors offer more torque and for a heavy truck like a 1/8 truggy, you need torque or you will just kill your motor quick.
The Tekno Lektron motors are made for 1/8 buggies. They're actually quite small for a 1/8 truggy. I haven't tried one, but honestly think it might not be enough. They're rebadged Medusa 36x60mm motors...about the minimum size for a 1/8 buggy. It might work in a 1/8 truggy if you don't gear too aggressively (keep it in the low 30s). There isn't a huge array of 36mm motors that will work for truggies. Some decent ones I know of have been discontinued. There's the Feigao XL series and the copy Keda (KD36) XL series which will work, but they tend to run hot or at least pretty darn warm. But they're cheap and may be worth it if you can't find anything else and don't want to invest in another motor mount. And they're fine as beginner motors. Orion/Kyosho offers a decent 36x75mm motor, but it's pricey.
Good luck and have fun.