Front springs

[5150neo]

This seems to be a topic that not too many have concrete information on. I'm upgrading the springs on my 91 model and have installed 12inch x 3inch ID x 225lb/inch on the rear. Eibach #1200.300.0225. On the front I need a 10inch x 250lb/inch spring. I am obviously going to have to use a strait/parallel spring. My question is does anyone know what the interior dimention is on the upper or top of the factory front spring? And if anyone has done this to their car, what spring manufacturer did you use? I'm currently running Spax dampers with their spring seats.
Any info will be much appreciated.
Cheers
John

[newburymess]

250# on the front seems a bit light......track cars are using 800# Eibchs

Steve, '95 S4s

[5150neo]

The majority of the time the car is driven on the street. So I wanted to go with a spring that works well with the Spax and also is not too harsh. So far the 225# in the rear is a vast improvment over the factory spring. It will do just fine for the occasional track day. So yes, 250#-280# up front. At least until I decide to install a roll cage, fuel cells, fire system, etc..
So, do you happen to know the ID on the top of the front springs?
Thanks
John