Your totally correct Greendog.As soon as you heat any"heat treated" spring steel it has to be returned to the pressure oven to be "re tempered" to it's required rate,same goes for sway bars,leaf springs etc.
Although doing what our friend from SA has suggested it will give you the ride height you want,however the spring rate of tension/recoil will be lost causing the spring to bottom out as happened to your mate with the Rolla
Keep Smiling
Cheers

my mate did that to this to his corolla and the spring coils were just slapping together.maybe he 'overcooked em'.i always thought heating springs would ruined em.even when cutting em i try not to let heat up.

since you cannot retern the springs (hope you havent choped them yet) there is an alternitave

You stop the car someware level, Take a gas torch and heat the springs up on the botom. Do this in Frunt and rear at a 180deg to one another. First front and then the rear. the car wil start to drop slowly piling on coil on one another. Do this until you reach the desierd hight, and then the other side of the car.

Take a smal water spray bottle to kil poseble flames BUT dont cool the springs for they will loos all strength, let them cool by them selves and see.

if your still unhappy youve lost nothing, the springs are worthless to you anyhow.

we have done this many many times no prob.
PS; remember only to heat them up NOT cut them!!!

Cutting them scroos up the wheel alingment
and as for shorter shocks Mrk 1 Golf inserts work grate

ok did you keep the standard strut top bearings ?

how did the top spring perchs fit on the struts ?

hey casey is that as low is can go?how does it drive.

im running the otomoto kit on standard 120y struts non shortened and this is how they sit with 12s
and they are easy to make just need a grinder and only needs 2 welds for the whole deal

i always thought you choped them in the base not the tops

yea i asked my supplyer today ,and they wont take back the springs so im chopping them ,is it truenthat you chop the top of the spring so the bottom still sits in the perch properly ?

I use an Otomoto coilover kit on the Sunny sports sedan,with 300lb. springs(holding up a CA)and am very pleased with the result.I made up some sort of bearing set up for the tops,but i see they now do a kit to suit anyway so your sweet there.As the guys have said the strut tube will need to be shortened to suit your height along with a new insert.As they also said good luck getting it engineered if you are keeping it on the road or be prepared to run the gauntlet.
It,s all up to you and your measuring tape.
Even i have been sucked in by the likes of King springs and there "so called" lowered springs,you see all there measurments are based on original new factory springs that are now 30+ years old and sagged to buggery and in most cases running on 13,14 and 15" wheels not the 155x12,s they arrived on our shores with.
Cheers

ive got the elcheapo ebay coilovers in my car, and a couple of mates cars and they seem to do the job fine. have to make up some top spring perches for them as they are supplied with plastic ones....yeah thats just a little dodgy
the springs they come with as stupily heavy, 400-500 lb if i remember correctly but new springs arent that expensive
only seen them to suit 51mm struts though so you would have to weld a sleeve onto the standard struts to get them out to that size
and at around $120 for a set of 4 they are stupidly cheap, which is what would turn most people off im guessing

oh and you are going to have to fit shorter shocks to the struts, preferably cut the strut down to suit a shorter insert, otherwise no matter what springs you have in there or what setup it is the springs wont be captive and will be what the police call illegal (so is any unengineered mods to the suspention...but meh)

that last part will apply to ANY setup that you use to get the car low