Just installed a new 454 crate motor with an Edelbrock performer series carb. After the motor has reached operating temperature and is turned off it diesels. This is a low compression motor that is supposed to run on regular unleaded. I was told to use premium gas and the dieseling would stop. It didn't.

Can anyone give me any ideas to try next. I suspect something to do with the carburetor but I am not an expert and have never experienced this before.