i spent all day putting new springs on mine today. thought i would go with the isolators this time thinking the sportlines would drop too much... so put them on and it wasn't low enough. took the front iso's out, didn't wrap them in anything (maybe i should have though), and for now the back one's are in but i may end up taking those out too. probably gave me about an extra 1/2" drop up front like Niteryder85 said. i just took out my hodge podge spring set up out (pro-kit front w/ h&r race in the back) but it wasn't low enough for me. i had that set up for a year or so no isolators and never sqeaked. but tape or a bike tube or something is a good idea, it can't hurt to keep a potential annoyance from happening especially when it can be an arduous process to re-do the springs