Hi unless you have V blocks and dial indicators and a height gage its hard to check the amount of stroke ,you may want to try this and it will get you very close .With the heads off and the piston in place rotate the engine over to TDC and measure it with some dial calipers then rotate it to the BDC and measure it again.Do this to both engines and then you will have a better idea if there the same or not .Digital calipers aren't very expensive, Under 20 bucks at most auto parts stores .1.6 mm is .063 rounded off so it should be noticeable even using a 6 inch scale.Hope this helps.