Hello all I am thinking about getting a 5.7L motor out of a full size Chevy truck. The motor has roughly 100,000 miles and runs excellent as is. I was thinking about doing a cam swap on this motor and everyone seems to go with Comp Cams XE274 but I was thinking since this motor is already a roller I was going to go with XR276. Now I know the heads need to be cut for larger springs and tapped for screw in studs but if I use self-alligning rockers do I need the heads machined for guide plates to? Or is it better to have them cut for guide plates and use non self-aligning? I am hoping for around 400 flywheel HP and about 350 at the rear wheels. What do you think it should make? The CR should be right around 9.5 and I was thinking about getting a shim style gasket something like .015 compressed thickness to raise that a little. And I planed on self-porting the heads and still debating on having them cut for larger valves any ideas? This build I am hoping to stay under 2500 for everything.