Crank grinding is a standard service in motor rebuilding. It's done as needed, because the surfaces that rub on your bearing shells, eventually wear over time and are no longer perfectly round, or flat from side to side.
There is supposed to be always a little radius in the corners of the running surface; this is called a "fillet radius" and it helps transfer the stresses evenly through the metal. So if you look at a crank and see these rounded bits next to where the bearing runs, it is not wear but design.
You don't know if a crank needs grinding until it is cleaned and measured with a micrometer at many points. Then it is reground the minimum amount necessary. Typically, the rod bearing surfaces (journals) may get redone at the same time.
I paid $136 for ACL rod bearings, mains and cam bearings a couple of years ago. That may have been trade rates - not sure. The gasket kit is a separate item from the bearing sets; I haven't heard of them being packaged together by the company.
There are some common problems in rebuilds. The motor after machine work needs to be surgically clean, no ifs or buts. To achieve this effectively, every plug needs to be removed from the block and you end up scrubbing it with warm water, dishwashing detergent/sugar soap and engine cleaning brushes to get it spotless. Then you need to rinse and follow up with a light oil on everything to prevent corrosion.
People often fail to clean out the rubbish from the water passages before the block goes in for rebuild. After it's back together, the crud repositions itself in the motor and causes overheating issues.
Every bearing should be checked; boxes and packets are not to be trusted. That means you Plastigage every clearance possible before actual final assembly. Also, if a surface says clean and dry, that means NO OIL FILM. Prepsol can be really handy for degreasing that film off things. Fail to remove this and you run increased risk of spinning a bearing.
Lack of proper attention to oil seals is an issue; this will create some fun later when it ruins a clutch. Note that Permatex #3 is needed for flywheel to crank bolts, and that these bolts are ¼" longer on a manual.
People don't finish hone to match the recommendations of the ring manufacturer, and the bore eats the rings or vice versa. They also fail to determine compression ratios and deck the block appropriately. Or, when it's started, they don't follow the manufacturer's recommendations to break in the rings.
And my biggest gripe - folks who fail to set the motor up as they go. The engine should be ready for the head and valvetrain with the #1 piston at TDC ready to fire. This makes everything else easier.
Other big complaint is not verifying everything before you startup. You need to confirm that ignition is working fully, fuel is working fully, all before the crank turns once! Cranking and cranking just wears the assembly lube off and you might as well have not bothered with the rebuild.
One thing I forgot - a lot of performance cams require a hardened cam gear. Crow supply this and it's about $60. Check with them, when you ask about cams.
More info than you needed!
The Ford sixes have torque - use it!
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