they are safe as a bank. longer u bolts are fine. spring rate is fine although i would recommend chasing down a set of ute springs for a bit extra stiffness as they have an extra leaf and your car will be 2" closer to the ground.

axle tramp is probably the main reason some people are against them but in the whole time i had them on my wagon, i never had an issue. well over 60000km's of use, both loaded and unloaded and long and short trips.

for looks and everyday driveability you can't get better value.

But if your going to spend the money for lowering blocks, then go to the trouble and expense of tracking down the ute springs and swapping them over, your better off just getting replacement lowered springs. THe ones King do are fitted with the extra leaf too.

OK my two bits worth..... I have driven over 500,000klm in 3 different e-series wagons and just bought another one! Dont lower! OR.... get ute/van springs from pick-a-part for $34 as I just did again. lowering blocks will be fine esp if they are longer than the u-bolts... ie they are kept centered by the u-bolts. One thing I have noticed was the shocker rubbers have a hard time with the heavy springs and may disintegrate. I used to carry a lot of tools etc plus gas tank so the rear end has a hard time. before uprating the springs my cars used to bottom out a lot and it never happens now! The 1 ton springs are very tight and the car handles much better in combination with front lowering and sports struts. If you bounce on the tow bar it barely moves and the ride is still pretty smooth asside from speed humps.

you make it sound like its a major task. is that because you live in tas and there's only 1 wrecker there or something. i had no trouble sourcing ute springs for my ba. took all of about an hour to fit them as well. my xr6 wagon i didn't have to as they come with 5 leaf rear.