Almost all very old cars have horrible aerodynamics, which will cut the range for an EV conversion about in half. Yes it's that bad. It's still better than burning fuel though... Usually you don't drive these cars to cross the country, so 8 this they are great candidates for a conversion, actually.

People have swapped newer engines into old cars forever, this is essentially the same thing.

Have you weighed a modern car?

Ironically, most modern cars don't weigh significantly less than their forbears - they've just swapped what the weight is used for.

So plastic bumpers weigh a lot less, but now there are 42 airbags and their controls, air-conditioning, power steering, power windows, power mirrors, remote gas/trunk/hood release, tire sensor systems, tilt steering wheel, and power brakes are nearly standard since the 90's, adding a couple hundred pounds. Then there's the massive strengthening of the A/B/C pillars for rollover safety (notice how modern cars have major blind spots in the front from those pillars compared to even a 1980's car).

And today nearly all cars are AWD (perhaps 500lbs), and then things like power seats, heated seats/steering wheel, folding rear seats, even battery cooling (seriously, I've seen Honda add a cooling fan for the battery, apparently the compact space doesn't permit enough airflow, so there's a fan, a sensor, ducting, and controls).

Some weight examples:

2020 Ford Taurus curb weight: 4000 lbs.

1974 Ford Maverick (4 door) curb weight: 2800 lbs 1974 Ford LTD: 4277 lbs (a larger and more spacious car than a Taurus).

BTW, the Taurus weighs about as much as a mid-size pickup such as the Toyota Tacoma @ 4200lbs or the Honda Ridgeline @ 4436 lbs.

This isn't a complaint, just an observation that franky surprised me when I randomly looked into it recently.

Unit-body construction saw extensive growth through the 60's and 70's, so pre-60 cars may weigh more, though I haven't done much research into it yet. Those vehicles had fewer amenities (like heat!), so it's hard to compare.

yeah, it will end up being like a F150 Lightning or a Hummer. HUGE amounts of battery packs and super inefficient - but still totally feasible. Just expensive.

Don't count on regen braking to help you, because the distance you need to brake in (eg. coming to a red light) doesn't change, but thr distance it takes to brake increases, so you'll end up relying on your real brakes a lot more. If you had unlimited distance to stop in, then you'd be right.

In any case, it's still a fantastic idea, especially as batteries keep getting denser and cheaper.

I feel that any of those downsides, plus any number of unknown ones are possible if you tried to convert an ICE car to EV. If that type of conversion were common, I don't think that would be a problem to the customer though. These would be cars built decades ago with gas engines in mind, they aren't intended to work at peak efficiency with the realities of an electric engine, and that's not the point. I think the point is you can breathe new life into older cars. I would love to have an EV old school jeep wagoneer. That would be amazing

SuperfastMatt on youtube has gone over exactly all the subjects you've covering in a fairly 3/4 assed (and humorous) way while actually tesla swapping a 1950 Jaguar Mk5 (the ugly one...). It's a pretty entertaining watch, as are his other builds.

https://www.youtube.com/watch?v=DxxaHYlCuN8&list=PLoTU9_iCGa6i_C38pwQyg0pBGoov76NNv&index=1