If ford spent the hours and time measuring and double checking tolerances that (good) engine building shops do then the cars would cost a good deal more. Imo a engine built by a good shop would be way more balanced and better built then an assembly line built engine.
I agree that local shops spend way more time machining and measuring but I believe Ford still does it more accurately due to the equipment involved. Just take your typical machinist's mic or dial bore gauge, which has .0001 accuracy at best, and compare to the .00004 that Ford is systemically stamping on every block and crank. I tend to believe Ford is measuring using automated optical or laser measuring methods. Aftermarket bearings are only offered in 1 thickness, but Ford installs 5 different combinations to keep the clearance in an extremely small range. Ford also dimensionally checks way more measurements than a local machine shop. I think the days of boring a new block just to improve the accuracy of the machine work are over.
I took some dimensions off of mine to verify a few things, just for the heck of it. Otherwise just clean and assemble. Keep in mind that the more you do to it, the more fault potential you introduce. For instance, the pistons sit below the deck by .015 IIRC. I would like to have built mine to zero deck to increase compression and reduce quench. However, there is small chamfer at the top of the PTWA, presumably to aid in ring entry during assembly. If you zero-deck it then you have to cut the chamfer into the PTWA lining, and then you have to ensure all the metal shavings have been removed. Just one remaining metal chip can trash an engine. Is the risk worth the gain?
When using a coyote crank in a 5.2, you want to run a 3.700 bore coyote piston. The voodoo piston has a shorter compression height vs coyote, to compensate for the longer stroke of the 5.2 crank.
With that close of clearance, it seems as if the cylinder expands more than the piston at operating temps. Meaning the .001 opens up to .003 as example.
