Originally Posted by
Beav93
how would i measure the stroke??? what would the difference in the two be?
Bring engine to TDC #1 and pull the spark plug. Stick a long dowel or rod through the spark plug hole untill it bottoms against the piston and mark the rod. Rotate the engine on half turn and insert the rod again and mark it. Measure the difference between the marks, that's your stroke.
3.50"=351, 3.98"=400.