GM H body rear spring question

I have an 89 Lesabre 3.8 front wheel drive that needs better springs in the back for towing! was wondering if someone knows if say a pair of caprice or other gm rear wheel drive rear coil springs would work? seems there are plenty of those to be had on ebay. impala ss or police package springs would be nice, but i dont know if they will work or not! i need more capacity/lift in the back! thankx