Yes, don't be swapping main caps around. Unless of course you got them mixed up in the first place. You need to check for dimension, and out of round of the bearing bores in the block with the caps installed and torqued to the proper spec. check the crank journals. Install the bearings in the bores without the crank and once again, torqued to the proper spec. Set up the dial bore gauge with a micrometer. You should see some eccentricity with the area 90 degrees from the separation line of the bearing cap being the number you want to see, while if you turn the gage right or left it should get incrementally larger somewhere in the range of .002" (I can't remember for sure, but just look it up). If it comes down to it you could just turn the one journal down to the next size smaller and get a single bearing. (remember in the inlines, EVERY journal is different size) If you cut the cap, without line boring, you would essentially be making the hole oval, assuming of course it was round to begin with, not to mention off center. To summarize, there are a few issues that could be at play here. the bore is too big, the bearing is out of spec, or the crank got turned too small. Each situation requires something diferent, if the bore is too big, you will need to have the cap(s) cut and line bored, the bearing would need to be replaced ( I would assume at someone else's expense), and if they ground the crank to the wrong size, I would assume they would be responsible for that as well, I do know if it was mine, they would find me another crankshaft and make it the way I was paying them to make it. I got very cynical during the rebuild of my last engine, I made so many trips to the machine shop, I had to take the head in 4 times before it got right. The cam grinders lost my brand new cam, that had never been in an engine, never did find it. If I had the money, I would buy all the equipment and do it myself.
