I have a buddy who tore apart the engine he got with an 85 Monte Carlo he had just bought. He had a bunch of go-fast parts and he wanted to rebuild the 305 that came with the car and hop it up a bit. As he tore it apart he discovered that the engine had a .030 overbore and that the motor looked like it did not have many miles on it since the rebuild as there was still hone scratches and there was no noticable ridge at the top of the bores. So, the motor had obviously been torn apart before to get rebuilt. As he took out the crank and set it on the concrete, he noticed it made a high pitched ding rather than a thud. He took a wrench and tapped the crank, and it rang like a bell. He then compared it to the camshaft which made a thud, so he automatically assumed that someone put a forged crank in it when it was rebuilt. I told him that cast steel cranks can also ring like the forged ones, and that some stock motors came with cast steel cranks as opposed to cast iron. We both agree it is not some cheap cast iron crank, but none of us are certain what it actually is as the casting number is too garbled to read. Is there any way of knowing what crank this actually is? He said that if it is a forged crank he will put it toward his circle track 355 project, and if it is cast he will just use it in his 305, so he really needs to know the difference.
Thanks for the input