In my opinion there's errors on both parties here. If Wisco recommends .005 clearance then the pistons should have been 4.495 plus or minus .0005. Because the STD,. bore should have been 4.500 for these pistons.
I never run .005 clearance on any engine unless they are hyper-utectic pistons. Every engine i build has .006 for gas and .007 for alcohol, .008 for blown alcohol. I ask the the person who bores the cylinder for me to leave a .001 or .002 so i can finish the cylinders myself. I once both a rotating assy from shaf. it cost me more than if i would have piece milled it. I'm not saying they are bad but they are busy and i doubt if their inspection is all that good.
The .002 taper is unforgivable, but the piston could have wore .0015 in 70 passes, but i doubt it.
The b/blk 476" i just put together, i ask the machine shop to give me .007, to the used pistons i had. It came back with .009/.010 clearance, was i pissed yes, but the owner of the engine sent the block to one of his friends, that he trusted. I showed the owner the dimensions and told him the possible problems, IE: piston rock less sealing etc. He said o'k i f**ked up but didn't want to fix it with another blk. or buy new pistons. I file fit the rings to .024 and put it together. well the engine ran 10.44 the first time out without good tuning, it will run low 10's next time out i'm sure with 3700lbs.
O'k enough, if it were my engine i'd just put it back together and go racing, not spend another $, it will run atleast as good as it did before when you were happy with it. You're not losing more than a .1/tenth with these problems. But do agree with you they should have never existed.
JMO
Zip.