I have recently been working on a 85s head for my x1/9. I am chasing higher rated valve springs. I have seen " Isky performance springs" listed for x1/9's on a Fiat distributors web site. As far as I can tell Isky does not produce valve springs at standard specs for any 1500 Fiat, but they do produce a BMW double spring for a 2002 316i that is almost a perfict fit (99%) with a higher spring rating.(serial number 625/626). Can any one confirm is this the same product people are sell as fiat performance springs. If so I am sure many Fiat owners would be interested. Thankyou.