The side clearance is of huge import as is the wrist pin fit in the piston end of the rod. I was surprised when I did the last engine by the taper on the wrist pin bushings when miked as opposed to the feel method.
As for the rod fit with babbitt, is was common to use prussian blue and rotate the crank then reinspect for tight spots where the blue was thin. A scraper is used to fit the babbitt onto the journal and it is checked again fot round and fit. This is really important if you are refitting runin rods. Hopefully the rebabbitted rods are true but when torqued, things distort and this can result in warp of the fitting surfaces. All of this is best done before you hang the crank. It will work with the mains as well. The end play on the crank is also important and there is a thrust plate which I had to replace on the 248 GMC motor which I just did. This plate was worn beyond tolerance and I got it from Patrick in Arizona. If you call him, he will share alot of experience with you regarding your project. On my last 216 the rocker oiler pipe was a nuisance and I suggest you follow the oil path and clean all of that out while you are apart.
