To be honest, I didn't change any of the valve terain, not even the valve springs. However, I would recommend you to change the valve springs to compcams suggested springs. (The stock ones valve floated at just over 5000rpm) The stock lifters, pushrods, rockers, and heads works just fine with it. I used a 360 cast 4 barrel intake manifold, (port matched it to the 273/318 heads) with the same 600cfm vac/sec holley you are planning on running, and flow tech headers. I was in love with that 318! And it was relatively stock, and cheap to build. I would recommend the xe268, or cam with similar specs to anyone who wants a cruiser with strong power in the low and midrange. The idle sounds nice and it compliments the power rpm range that all the stock parts are made to operate in.
