brizie i can't actually remember now all i remember was that the 200 or 220lb 10" springs made the difference on the rear for me - they are not so nice and are a bit bangy on the road on the back, but stopped it squatting and catching the rear arches.. and it handles nice

when i spoke to the GAZ guys (and i know little and nothing about these things) at Autosport a year or so ago, they reckoned that you can go too hard on the rear and it gets to the point of being detrimental to the handling)
Personally, i like mine how it is now - think Tim Butch went harder on the rears, not sure how it worked out for him?? he goes faster than me
Mine is also adjustable on the front end - depends what you want to go for

Posted these before but shows the difference:

On Koni;s it used to be floaty and scarey:


On Coilovers and adj TCA's:


In a straight line, it used to scrub the rear arches with the GAZ springs:


nothing changed, just rear springs c/o dingy&kia