918 Valve Spring -update
Has your friend looked in to Pac springs? They made the original 918's(the ones that don't suck) for Comp. They aren't priced too bad either, unless you go for the nitrided ones that are good for .650 lift and run $326 a set, but the .600 lift capable springs are $183.71 a set, part number 1218-16.
SDPC has a vergood deal on PAC 918's as of now...look here:
https://ls1tech.com/forums/sponsor-sales-specials/747147-new-beehive-600-valve-spring-sdpc.html
https://ls1tech.com/forums/sponsor-sales-specials/747147-new-beehive-600-valve-spring-sdpc.html
i have been runngin my 918s for close to 3 years on 3 different cams all in the .59x lift range . patriot performance makes some good springs. hit up gunnar here on the board and he wil hook you up .



