Roadrnnr69 and Styleelements...Don't take what I've said here as bashing, that's not what I intended. Just simply discussing and comparing the 2 setups.

The Irons' suspension is nice and I'm sure works well, but the cost and the questionable legality in stock suspension classes is what steers me away from it. Just b/c it can bolt in does not mean it will be legal for ss classes.
If the car came with leaf springs, it still needs to have leaf springs under it according to most class rules. Don't think they won't DQ you even if you bolted the system in. Like Big Squeeze said, you can make ladder bars bolt in, but it won't be legal.
No matter how you slice it, Cal-Tracs are 1/2 to a 1/3 of the cost of the Irons' setup and will likely go just as quick to the 60'. CHIP