Kinda depends on what you want to use it for. A high-winding motor (like in a dragster) would like a little more bore with a little less stroke. A stump-puller would prefer more stroke.
i think it is 4.000 and 3.48 but iam not sure I know the bore is 4.000 but i am not sure about the stroke.
torque specs 350 Chevy heads65 lbs
3.48
180 degrees is optimum
Atk engines com or 350 Chevy engines com
3.48"
3.480 inches
4 inch bore and 3.48 inch stroke. Do a Google search for more info. http://fourwheeler.com/techarticles/128_9712_chevy/index1.html here is the link for your specs A great resource for Chevy V-8 engine specs is www.mortec.com
The Bore of a 350 cid engine is 4.00, the stroke is 3.48 inch..
4.00 bore 3.48 stroke
http://www.boxwrench.net/specs/chevy_sb.htm
4.000 inches -- same bore size as a Chevy 350, the difference is a 327 uses a 3.250 stroke and the 350 uses a 3.480 stroke.