Turning a crank over by the balancer bolt works until the bolt starts to loosen, and on an engine on a stand there is nothing to hold it against. This adapter bolts to the balancer face and gives you a proper drive point, which is what you want when you are degreeing a cam and need to creep the crank a couple of degrees at a time.

Proform 66782 Engine Rotation Adapter Features:

• Fits Chevy V8 and Ford V8 engines.
• Bolts directly to the harmonic balancer.
• Accepts a 1/2 in. breaker bar or a 1 in. socket to turn the crankshaft.
• Suits engine assembly work and camshaft degreeing.
• Machined from stainless steel.
• Sold individually.