If you are building a stroker mock up the entire engine without rings and gaskets to check all clearances and measurements before your final cleaning and assembly. Then when you have done all your final measurements and grinding on the block and heads for pushrod and connecting rod clearance take it apart and clean it all again. Keep cleaning it until the white paper towel comes clean when wiping all your fingerprints off of everything.
I always fit the cam first before anything else goes into the engine. Finally NEVER EVER install an oil pump out of the box without deburring and cleaning the passages first. I always "port and polish" my oil pump passages with a small dremel tool when I clean it and make sure the relief valve works smoothly.
Building your own engine is just about the most rewarding thing you can do for yourself
Gus