There have been multiple engines put into VK 30s. A couple of Chevy V8s , RR Alison turbines. Continental is popular. The two I’m familiar with in passing was an Allison that was based and ended up crashing at my airport because of a AD that needed to be one on the engine, and another with a Continental Voyager engine. It’s still a project. The last one completed was with a Allison turbine a couple of years ago.