'07 to '06 suspension

I've got an '89 Tercel with 250,000 miles on it, still going, still getting over 35 mpg.  My parents have an '06 Camry V6.  They are looking to increase the load capacity by a few hundred pounds but don't want to add any of the coilover shocks (the cheap ones sold at jcwhitney) or airbags.  I was thinking that the suspension from an '07 CamryHybrid would do that since the Hybrid is 300 lbs heavier.  It has stiffer suspension to compensate.  Will '07 springs work on an '06 V6?

Are there any aftermarket springs that will stiffen the ride (and increase the load capacity) without lowering the car?

Thanks.

I wouldn't bet on it- just because the entire car itself is all kinds of different..different height and probably way different mounts and ratios. But hey! maybe you know something that i don't?... good luck!

Thanks for the reply,
that's what I had expected.  I'll either end up getting stiffer springs or ask the stealership (though I doubt they'd know/tell me)
If the springs are the same dimensions they should work on '06 shocks and struts, I could just get some firmer ones to compiment the stiffer springs.

are your parents  going to be tow? hybees 300 lb  weight difference is mostly in the front of the car. you may also want to think about adding a trans oil cooler.

    The dealership told me that the springs would give a very harsh ride compared to stock, didn't say weither they'd fit or not...I decided against it prior.  THey're not towing anything.  Just planning a long trip with 4 adults and a trunk full of heavy stuff and it exceeds the weight capacity of the car by around 300 lbs.  They don't like the idea of driving (around 1200 miles) with an overloaded car for safety reasons.  I keep searching for a solution.  The stronger suspension would be beneficial besides for the trip anyway.

i would concider those air bags. if you put stiff springs the ride would be stiff  like you said.... so what will happen when they get back from their trip and drive it everyday with just the two of them....that would fell like riding a mr2 spider...better yet maybe they should rent a SUV.. no strain on the transmission...more room....more room means  more comfort...and more important you're of the hook on having to install anything.