Slide the connecting rod up against the left or right crank web.  Position a dial indicator at the thrust washer surface on the wrist pin bearing end of the connecting rod.  Without sliding the con rod on the big end of the crank pin, measure the left to right wobble of the wrist pin end of the rod.

The small end wobble on a new OEM rod is usually around .030" to .040".  We find the small end wobble on most new Hot Rod connecting rod assemblies will fall in the .020 to .060" range.  .020" is too tight for a modified or stock engine with a pipe.  If I get a Hot Rod that has more than .050" when it is new, I send it back.............I do not know what they do with the rejects.    Customers buy a lot of rod kits on ebay and send them to me to use to rebuild their cranks. Of these rod kits a lot of them are at the high end of the clearance range. 

If the small end wobble is .060" to .070 there is not much life left in the con rod assembly.  If the small end wobble is .080" or more, the con rod assembly needs to be replaced.