With the engine block for our 455-based stroker mule engine completely machined, Craig Wise of RaceKrafters will now work on the rotating assembly, which includes the crankshaft, connecting rods, pistons, rings, and rod bearings. Our mule will enjoy all new internal parts thanks to a stroker kit sourced from Butler Performance that consists of a forged 4340 Eagle crankshaft, Eagle connecting rods, Butler-designed Ross forged pistons, and Total Seal rings. Thus, many of the procedures that would be required to retain used parts do not apply, especially since the Butler Performance assembly comes balanced already.
Since many Pontiac hobbyists may choose to refurbish the stock parts during a rebuild, this article covers the procedures in-depth that would apply to a new or used rotating assembly. This way the readers can have a full understanding of what is required to properly prepare a rotating assembly for a Pontiac engine. Also note that for a proper engine build, the new parts need to be checked and reworked for the exact application. You cannot just take an engine part out of the box and slap it in place.
So, is it better to buy new or retain an original Pontiac part? If your engine is all-original, the crankshaft and rods are in good shape, and you’re doing a stock or mildly modified build, you can have the machinist perform the proper tasks for them to remain in service. The sticking point often is that the labor charges come very close to the cost of a new, mass-produced connecting rod or crankshaft. But keep in mind that the new parts will require some expense to become ready to install. For example, a new or used crankshaft will need to be balanced.
 Here’s a rotating assembly...
 Here’s a rotating assembly from Butler Performance to build a stroked 455. It features a 4.250-inch-stroke, Eagle 4340 forged steel crank with 3.25-inch mains, Eagle H-Beam 6.800-inch forged rods, forged Ross lightweight pistons (4.155, 4.181, or 4.211 bore size), 0.990 Ferrea forged and tapered pins, file-to-fit rings, rod and main bearings, and was internally balanced. The price is $2,049. We’ll get into a deeper description of the individual parts in the upcoming assembly article.
The greatest price disparity will be found with the connecting rod choices. You can rework the old rods and retain the press-fit wristpin (stock replacement cast pistons and the TRW/SpeedPro replacements are not cut for floating pin-locks). The upside is that your engine will still have original Pontiac parts. Talk it over with the machine shop and have it provide a ballpark price once it confirms your parts are usable. If, however, you plan to make substantially more power and use floating wrist pins with high-performance forged pistons, forged rods are usually a better investment.
The following steps are what is required for a proper rotating assembly to be installed in your engine.
 After a careful visual...
 After a careful visual inspection, the piston dimensions are confirmed. The diameter is measured at the skirt with a micrometer.
One of the first places the machine shop will inspect on a used crankshaft is the keyway that holds the harmonic damper. If the damper bolt was not torqued properly, the crankshaft sprocket will be driven by the key instead of the bolt friction. In addition, if the flat washer under the damper bolt is distorted or dished, it should not be reused.
The machinist will visually inspect the snout threads for damage. If any exists, a determination will need to be made if a repair can be accomplished by chasing the threads or installing a thread repair insert kit. The flywheel flange bolt holes will be checked. The crankshaft will be cleaned, and the threads chased or a repair kit will be required, and the rear main oil seal surface will be examined for wear. Wear sleeves are made for most if not all Pontiac engines.
After the visual inspection, the crankshaft main bearing journals and crank pins will be measured with a micrometer. The crank pins are the area that attaches to the connecting rods. If all looks good, the crankshaft may then be mounted in vee blocks to check for bend, snout trueness, and flywheel/flexplate flange runout.
 The wristpin dimension...
 The wristpin dimension is recorded and will be used for small end clearance and piston pin-bore sizing.
When examining a crankshaft, the shop will also check for anything that looks abnormal. Any nicks, dents, or pits in the journal outer diameter must not exceed 0.005-inch or have raised metal. Any journal outer diameter score marks must be at least 0.125-inch from the fillet tangent point, a maximum of .010-inch wide, and circumferential, not axial.