Truer words have never been uttered. You guys should be grateful to Tony for learning this one first-hand and sharing this info publicly. Who knows who on this forum may also jump into the aftermarket block solution. Hopefully his efforts save someone else a headache.

This is actually really common with the $12,000 crate motors. The manufacturer doesn't know what equipment you'll be running in them, so they give you a little extra material in the bores to be machined to fit the stuff you've got. You could have a $1000 crankshaft that you want to use that's been turned down smaller-than-stock, and a stock bore wouldn't work in that circumstance... so they cast a little extra material in there to give you room to play with. Even in cases where the motor is assembled, the people who sold it as a package don't know that EVERYTHING they used to assemble it will make it into the final build.

Having a tag reading "put oil in it first" is really misleading if that's the crank it shipped with. The end-user should ALWAYS either machine the block to known specifications, or in cases where the build is blue-printed, verify that all the measurements are correct. There is no way to know for sure until you have verified everything YOURSELF.

.0015" is still a bit on the tight side of things, but it's probably ideal on a street-driven motor, and it's very close to factory specs. That's what I spec'd my motor to when it was built, and I have 35,000 miles on it now without any issues. If you're trying to be the dyno king and eliminate as much friction as possible, or milk every hp you can from a race motor, you can get away with as much as .005" on a main journal clearance, but it will be more susceptible to causing pre-mature bearing failure or damage from vibration at high rpms. A tighter clearance usually yields slightly better oil pressure.

Lance, I thought you were referring to how we got Tony home. :P