If you install a stroker crank +3mm, or a +4mm crank, and you use the hardware that is supplied. Like the spacer plate and two gaskets, you will loose power from the bottom to the peak. Using a 60mm crank( +3 ) the total transfer port timing is 138, and the engine will lay down. I would suggest that you think about other mods before a crank, unless you would like to spend the money to have someone set up the engine for the 3mm/4mm
If the builder you choose set ups the engine with a spacer plate, the trans timing will be way off.