Stiffer rear springs

[peggus]

So, as mentioned elsewhere, I'm converting a fiat 124 spider into an electric car. This means I will have about 320lbs of batteries in the trunk. While removing the gas tank, spare tire and rear bumpers goes a long way to offset the battery weight, the rear end is still sagging a bit too much, so I need stiffer springs in the rear!

I see a couple of options so I wanted to get your input on these.

1. Get custom springs wound. This is the more expensive option I'm hoping to avoid....Also I need to know the rate, uncompressed length and compressed length of the stock springs, Does anyone have these numbers handy for a 77?

2. Uprated springs. I hear that most aftermarket springs are stiffer and result in higher rear end, question is how much stiffer?

3. Use front springs on the rear, perhaps with a spacer. Would this even work?

4. Find some heavier car with springs of roughly the same dimensions and pick some up at the local pick-a-part. What cars might be suitable donors?


Thanks

-Peter
http://www.electric-lemon.com