I have an issue I have a big block 455 motor with an HEI dstributer in it my uncle put in a mister gasket Waite and spring kit but he put in the wrong springs and my car is still desiling when I shut it off please help frustrated

 

Dieseling has nothing to do with the WEIGHT and spring kit. You need to double check initial timing, idle speed, carb settings, etc. Hard to provide useful info without knowing more details about your car.

 

Dieseling is usually caused by a hot spot that ignites fuel to allow the engine to run on after the spark is turned off, hence the name. As Joe stated above you need to see what is causing this and it could also be as simple as excess carbon build up inside the combustion area.

 

You're probably talking about run on which might be too high an idle speed. If you advanced the timing at all the idle speed would have increased.