building a tough 393 stroker for my xd, and guy who building motor said comp cams has recentky released a cam with over 700thou lift, has anyone heard a motor with a cam like that its got to be close to a pro stock motor, how close to a pro stock cam is it if anyone knows, either way it'll sound really really p****d off

... having 0.700" lift doesn't mean it will be anything like a Pro-Stock engine. Crane have been offering Cleveland camshafts with over 0.720" lift more many many years.

What are you trying to achieve from your combo? What heads are you using? Manifold, pistons, compression ratio etc. They will be the determining factors for your camshaft selection.

my old man has a 393 clevo, chi 2v heads, custom cam 615 lift, it made 417hp to the wheels today, it was running out of fuel and needs a bigger carby, intune reckens he will get another 20+ out of it. needs a carby spacer as well.

So long as its known that you can over cam an engine ...

No point just having the cam in it, you will need the rest of the gear to suit. Not too mention the 2.3'' valves to suit.

I heard a rule many moons ago - measure the valve, 25% of the daimeter is the max lift WORTH RUNNING.

chi heads, high rise single plane manifold, a 950 methanol carby, je forged pistons, 4340 steel crank, manly rods, running around 12.5:1 compression could be higher, roller cam or it may be a hydraulic roller, roller rockers, etc.

I would just like to add to the above comment. As stated, when a valve is lifted to 25% of its diameter, the valve curtain area has reached its maximum, BUT, if you only lift to 25% you will be on the nose of the cam for only a fraction of a second and then you will be "closing the window" so to speak. So for this reason the lift is increased to open up the area under curve of the graphed lobe, and the time in which the curtain area is at its maximum is longer. You need to figure out what you want and go from there.

FWIW, the A/MD which makes almost 700hp and the SC/O making approx 1200hp that I crew on, both have cams with lift in the low 0.600" range, and both are SB350 chevs