I am looking at a 382 with 500 efi's. If properly maintained, what is the expected lifespan of the engines?

How many hours can the engines run until a valve spring job is needed?

How many hours until a top end or freshen is needed?

After being freshened, how many hours can be expected of operation?

Do the EFI's need to have valve springs done at the same time as the 500 carb motors?

Better question for the Tech. Forum.

You should get 450-500 hours out of a 500EFI bottom end.

Valve springs, no matter what the age or induction, should be done around 200-250 hours.