After testing my first attempt at a 4 gear modded tranny I decided to make a few improvements and also try another design I considered. I originally went with the "C" support for the idler because it is stronger. I also considered a spindle to hold the idler, which would be easier to make and be more compact.
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To help me line things up and locate where new holes need to go I decided to make a clear copy of the motor plate. I clamped the stock motor plate to a piece of lexan.

Used a thin sharpie to trace the holes.