gen 4 springs are totally different from any other gen. good seat pressure with strong retainers. ti int. valves can run a little tighter than gen1 and 2 with tool steel valves. think u will find .015 deck about max without sinking int. valves, that gets it right to the stock valve seat. .015 will work and allow degree. valve cover head surface and deck are not parallel from factory, angle milled so head must be indexed to correct angle to be milled. should run good with u doing the work.
Last edited by gazx10; 12-09-2014 at 08:44 PM.