Especially if you are trying to convert a vehicle that has not been converted by the community before.
So a conversion makes more sense as the value of the donor vehicle (either monetary or sentimental) goes up.
But, will the final results of your labour of love be all unicorns and rainbows, or a disappointing and valueless waste of time?
EV Designer is a fairly accurate physics model I created a while back that allows you to experiment on different drivetrain ideas before you buy, cut and hack.
Click the link to make a copy of the spreadsheet, then fill in your parameters in the grey colored cells (you can select MPH or km/h in the pink cell)
It tracks acceleration, max speed and range within a few tenths of a second/MPH with real world vehicles, eg Tesla Model S, 3 etc,
Don't forget to check the Cruise Performance estimate, especially if you live in a hilly part of the world. A lot of people forget that one

(I also added a lot of information in subsidiary sheets, so check those out too)