Quote Originally Posted by camaro_fever68
If it's a GM production block, you'll likely hit water before you get enough clearance for the 4in stroke. Try to keep the overbore to .030" also. Cylinders start getting really thin and close after that. My block sonic tested good enough for 4.170 overbore but I kept it at 4.155. I also had alot of clearancing to do to get the 3.875 stroke to clear. A small base circle is needed for sure and I still had minimum clearance on the cam.
I have never hit water but yes it can happen.