Same concept as one of our forum founders
https://ecomodder.com/forum/showthre...uck-36840.html
I also recommend looking at what hoopie did
https://ecomodder.com/forum/showthre...uck-34935.html
That said besides hoopie there are no completed and successful hybrid conversions listed on diyelectriccar.com
Which is the source for how others have converted.
For simplicity an in-line Motor like Ben has coupled with a $900 Chevy volt battery, charger, controller, dcdc, brake booster, manual steering rack plus the “gas pedal sensor” would be what you need at a minimum.
Good Luck