[Blackhauk90]

Well heres the situation.. I have a 351w with speedpro flat top pistons. The heads are world sr. 200cc.. 2.02 intake and 1.60 exhaust. At the moment i have an engle cam.. its like .498 lift and 268 duration.. 1.6 arm ratio.. I was wanting to move up to something around like .540-.560 lift and around 280ish duration.. I'm worried about the piston to valve clearance.. The pistons were not fly cut when the motor was put together.. I was curious if anyone had a similar setup and if they had to get the pistons cut.. I was sort of hoping i could just swap out the cam and not have to get the pistons cut.. Anyone got any helping suggestions?

[techinspector1]

Even if someone had done the exact same build, their answer wouldn't necessarily be valid for your motor. There are too many variables. Main bearing centerline of the crank to the rod bearing centerline could be a little different. Rods could be a little different length. Piston compression height could be a little different. Block deck height could be a little different. Position of the valve seats in the heads relative to the head mating surface could be a little different. Even using the same exact heads, the valves could be sunk in the seats further on one head than on the other one. The gaskets they used could be a little different. The rockers they used could have a little different ratio, etc., etc.

Each and every engine build stands alone. You must check the clearance on your particular motor.....yourself.