No it's not normal, and I would definitely look into what the issue is. Just a guess, but I wonder if they used the smaller 3/8 bolts typically used on standard 390/428 rods, instead of the 13/32 that was used on CJ/Low Riser rods? Is it a CJ engine, or are they CJ/Low Riser rods? Either way, I wouldn't feel comfortable at all unless the bolts were properly sized, installed (they should be press fit), and then the big ends resized.