RE: 27% Cessna 421 Twin Turbo Prop
Reza,
I use Wren turboprop motors and have encountered no problems. Excellent service from the factory. The build is going very slowly as I am very busy in the shop, but so far no problems. The short kit is excellent and the parts fit is true.
There is much to be said regarding which power plant is more reliable.........
Feel free to pm me if you have any further questions.