65 D100 /6. swapping in a BB. Have the correct BB (early 60's I am assuming) hyd bell/wheel/ NP 435 granny 4 speed etc. I am assuming this 'wheel is internally balanced. I have a 400 & a 440 & the torque converters on both of em have the extra weights denoteing externally balanced (I am assuming). Is there any way I can get one of these engines to drop in as is or do I need to find an earlier internally balanced 440? Thank you for your time.
If they are externally balanced you will either have to get the flywheel modified or find a steel crank engine or install a steel crank in yours. Somebody used to make a weight that sandwiched between the crank and the flywheel but I'm not sure who made it or if it's still available.
Externally balanced engines also have a different harmonic balancer too just in case someone installed a different transmission in the past and didn't know there was a difference. Cast cranks usually aren't drilled properly for a pilot bushing either.