No need to call Im here bud!
You can use your exiting case you only need a 23 spline input gear.
You will also need that if Run a r150f But you will also need my adapter.
The biggest problem with the R151 is that they are very rare. Had to find and you will pay a pretty penny for one.
Also you no be running the bell housing anyway you will be using a adapter bell housing.
If you go with the R150 you can run our adapter on the rear to go to a gear drive case.
Long story short run what you can find, & what is cheaper as the strength is the same.
