I'm in the process of purchasing springs for the F, so I had to do some digging to find the information I was looking for (mainly the available brands, the drop, and pictures). So I decided to consolidate that information into one thread. Input and feedback is appreciated.

Tein H.Tech Springs:
Part Number: SKC72-BUB00
Spring Rate Front: 7.7 kg/mm = 431 lb/in
Spring Rate Rear: 6.8 kg/mm = 381 lb/in
Ride Height Lowering Front: 25 mm = 1 in
Ride Height Lowering Rear : 15 mm = 0.6 in
Review: ???
Pics:

Swift Racing Springs:
Part Number: 4T906
Spring Rate Front: 9 kg/mm = 503 lb/in
Spring Rate Rear: 8 kg/mm = 447 lb/in
Ride Height Lowering Front: 25 mm = 1 in
Ride Height Lowering Rear : 15 mm = 0.6 in
Review: http://www.lexusfforum.com/forums/showthread.php?t=3338
Pics:

Eibach Springs:
Part Number: 8289.140
Spring Rate Front: ???
Spring Rate Rear: ???
Ride Height Lowering Front: 18 mm = .7 in
Ride Height Lowering Rear : 8 mm = 0.3 in
Review: ???
pics:

I'll update this list as needed. Pictures of each setup would be appropriated (side shot), or I might revert to stealing some from other threads :P

Hans

Looking at the available list, I'm leaning towards Swift springs because the seemy to have a similar drop as the Tein but slightly stiffer spring rates for a more controlled feel and less scraping

I am not on any springs, but Swift Springs have good reviews.

^thanks... there seems to be more interest in coilovers than springs for most people on here, so I might expand this thread to include all "drop" options available.

I know I have stated this before, but I love my Tien's. The ride is much more compliant and the corners...well hang on cause you can take them strong.

Ok, I've decided to go with Tein springs for my 08 ISF after reading all the reviews. Can anyone please provide me links for purchasing these springs at the cheapest price possible? Cheapest i've seen are about $209...thanks in advance for all the help!