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I think youll find that if your useing new parts that the crank and rods are well within spec limits, if your useing a reground crank, youll be far more likely to run closer to the outer clearance limits. side clearance on the rods is not super critical as long as you stay within reasonable limits, having a few thousands over or under the ideal spec does not seem to cause major problems in most engines. .006-.014 seems to work,reasonably well, I try fot the tigher end of the range but don,t lose sleep if I run into the mid range in clearances
heres the specs
btw heres a handy form to down load

keep in mind that swapping rods between cylinders can help sometimes and that theres an inner and outer side to the rods and rod bearings and that thers a radius cut on the crank throws and bearings
look very carefully at the picture below

the upper rod has the side that mates with the other rod showing upward
the lower rod has the side showing upward that goes outward toward the crank counter weight notice the beveled area near the bearing shell mateing surface

many rod bearings also have one edge thats beveled that side faces outward
its the space between the rods when they are on the crankshaft journal, here read this

the best advise is get a shop manual or at least a HAYNES MANUAL at the local auto parts store and follow the sugguessed clearances unless useing aftermarket parts (then use the manufacturers advise)
clearances (average sbc)
piston to bore depends on piston manufafturer and piston type but .002-.045 is the normal range (check with piston manufacturer)
rod bearings are normally .0015-.0025, I try for .002
mains are normally at .001-.0015 for the front bearing, bearings 2,3,4, .001-.002 and the rear main at .002-.003
rod side clearance is normally at .006-.012
crank end play is normal at .002-.006
cam button to cover I try for .010-.015 clearance
rings are normally set at .004 per " of bore,EXAMPLE a 4.03" bore would get a ring clearance of 4.030 x .004= .016-.017 ring gap
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