hi nz_datto... im going to be using crow cam springs which are available at crow cams cabelfield victoria these are used inthe 1 litre sprint cars over here most people ive spoken to have said these are a good spring and work well , these are also rated at 90 lb they cost me 82 aus dolars may be worth a try there also designed for the a12 and fit straight up with no problem .,..........cheers.......