No, retarded. It was common "back in the day" for the smog era engines to "run on" and "diesel" on shutdown. 71ish---on up just before EFI in about 85
Check timing do not retard it. Make sure carb adjustment screws are not too lean (or too rich either) Run as much timing as you can and recurve the dist or buy one of the "limiter plate" kits
