Cheap lowering springs for trunnions

and these fit in the stock location ?  would they work with the American body ? 

Be cautious with any changes to free height.  I got springs from speedway a few years ago and it looked good on paper and even when the weight of the car was on them.  The problem was when the weight of the car isn’t on the suspension, for instance when the car is being jacked up by the frame.  The lower spring cup would easily dislodge from the trunnions.  Maybe if you have a set of short shocks in there they would prevent it, but thats not really what shocks are meant for.  In my application (drag car) it wasn’t a good option unless suspension limiters are present.  

Even if the free length was a little short, it would ge easy to I stall a strap to limit downward travel... as noted already.

For about the same price (last time I ordered... but that was 7-8 years ago) you can custom order springs from www.coilsprings.com. They have all the old stock specs, so you can just order shorter than stock. They will calculate the needed rate to get the performance of a stock spring, or you can order a percentage above stock. For the old 60s cars (69 and older) 12% over stock improves performance without creating a harsh ride. You can feel the difference in ride, but just a bit. The decrease in body roll is amazing -- better than a sway bar! Those cars were sprung rather soft for the rougher roads and slower speeds back then, especially 66 and earlier. The high spring suspension design is very roll resistant, that's why AMC initially didn't use sway bars or had small bars, and a stiffer spring works wonders. For a 70 or later I don't think I'd go over 10% stiffer if you don't want a hard ride. In comparison, early 60s Rambler HD springs were about 18-20% over stock and rode like a horse wagon! Only for heavily loaded vehicles. I don't have the specs for 70+ car springs, so don't know how much stiffer those HD springs would be. The rates are calculated differently for the 70+ cars vs. the trunnion cars because the spring is a couple inches further in on the 70+ upper ball joint cars, not directly over the king pin as in the trunnion cars. That couple inches (to clear the top of the ball joint) makes a big difference in leverage, so the 70+ springs have to be stiffer.

That's great! And good info, didn't mean to sound like I was discounting the springs you mentioned. They have the advantage of being readily available. You have to wait 6-8 weeks for the custom springs. Other companies might charge a lot for custom springs but Coil Spring specialties custom makes all their springs. I'm sure they probably make some popular ones and keep a stock, but they make most to order.