This is actually pretty awesome. I have already converted my fat tire bike into electric. Love riding it. Thinking about building a custom all-electric cafe racer. Once I'm done with that I'll be trying to convert my Toyota ee90 into an all-electric daily rider.
So I want to do this and understand the motor/power train part well. I am more curious about the stuff around it, such as the gages on the dashboard. I have speedometer and tachometer on my dashboard. Do these get replaced? My speedometer has a small LCD that show fuel economy, distance to empty, tire pressure etc. So the question is how to you fit your new power method into what is a unique system design for your gas powered car?
As far as I know, yes you need a custom EV speedometer, tachometer that shows how much charge, and how many miles you have left.