Hi im trying to figure out what size the crankshaft bolt size is ❓ i am trying to break it loose on a 1972 oldsmobile cutlass supreme 455, thank you. 👍

 

The big one on the front, center of the crankshaft is 1 1/8".

 

Ok great thank you ❗️ Much appreciated 👍

 

Are you trying to figure out the hex head size or the thread size ? 1 1/8" sounds about right for the hex head of the bolt.

 

It's also torqued to 160 ft-lbs, so you either need to use an impact wrench or you need to hold the engine to prevent it from turning. I made a tool by welding a pipe to an old crank pulley. Replace the pulley with this tool and it makes loosening and tightening much easier.

 

Got it thanks again fellas❗️👍