This tool is an essential when doing top-ends or when building a new engine. Slide this tool into the wrist pin bushing in your rod, then rotate the engine to make sure the tool sits squarely on the crankcases. If it doesn't most engine builders will go through a rod-straightening process until everything is square.

Used to check connecting rod straightness with bottom end of engine assembled. Fits 1936-1999 Harley-Davidson Big Twins, all year Sportsters, or any engine with a .791" diameter wrist pin. Centerless ground in Milwaukee from premium US-made 4130 through-hard steel. 1/2" longer than other similar products on the market for easier use on both stock and big bore applications

To use:
Slide tool in wrist pin bushing
Rotate until tool contacts the crankcase.
Slide 2 small strips of paper under the tool and make sure they each pull out with an even amount of tension.
If corrections are needed, adjust (bend) rod until paper pulls out with even tension on both sides

As always, 100% made in USA. Fast Eddy Co. offers a lifetime warranty to original purchaser.