I have a bigblock that rope started fine with the head cut .050 and 35# valve springs. It still has the same cam (.246 duration, .260 lift) with a compression release. I have a new head that I got cut .080 with the same thickness head gasket as before (.020) but has 55# valve springs, and 40/33mm valves and it's ported. I also put 1.2 ratio roller rockers on it but I can't rope start it now. I've adjusted the valves over and over for .003 to 0 lash with no change. I took the cam out and the compression release looks like it should work, it's measuring .070-.075 higher than the exhaust lobe. Am I doing something wrong or where should I start working?