Looks like the Thunderturd will be a blast when it's done.
Naskart? Ehhh.... maybe not yet.
Given how much work it needs, it'll take A LONG TIME until it's fun.
Try and sell that Tecumseh and get a Predator 212. I know it's a big price jump, but it'll be worth it to have a brand new engine that's NOT A TECUMSEH! If you can get your fingers on a Briggs flathead that hasn't been killed to death, that'll probably give you a lot of service.
Wait, don't you have a 3.5 pony flathead hangin' around? Use that.