I have a question guys, and I don't feel like this is necessary to create a new topic for it, so i think this is the right place..

I plan on lowering my 1982 ST. First, i need to order some custom springs. The problem is, I don't know what specs to pick.

I found the stock springs specs here:
http://www.celica-gts.com/forums/index.php?topic=23973.0Someone posted 96 for the front sping rates, another guy measured 157...So I don't know what to think

I'd like something around 7kg/mm (400lbs/in) for the front, and 5 rear (285), with à 2.5(ish) inch drop.
-> How to calculate the free lenght to get this drop ? (considering i'd also go for shorter shocks)
Also: A french guy did the short stroke conversion on strut tubes. But, unlike this topic (
http://www.celica-gts.com/forums/index.php?topic=17320.0), he welded the upper part of an MR2 strut, to fit MR2 AGX. My question is: is it mandatory ?
Be gentle, I'm totally new to car mods.