Welcome to CHR:

Sounds like you are undertaking a avery ambitious project and your up-front research is certainly warrented and will prove to be well worth the time. Here's an article that may give you some of the information:

https://www.novak-adapt.com/knowledge/gm-crank-spacing

It has additional links that may prove helpful. Good luck and let us know some specifics of what your building.

Regards,
Glenn