[Perry S (Spokane)]

My engine is a '78 440. It originally came from a truck with a 4 speed. I pulled a 727 from a 78 Chrysler. I believe it had a 400, but not sure. Will this torque converter be correctly balanced with my engine? I know that mopar balancing has been tricky. I can't seem to find any documentation as to interchangability.
Thanks,
Perry

[David Robson (Admin)]

Cast cranks from the factory were externally balanced and were used in 440 engines from about 1974. All 400 engines had cast cranks. So you should be ok.

To be sure of what you have look at the crank damper on the front of the engine and the convertor in the trans.

[Luke (Luke)]

If you have an externally balanced crank and your converter hasent got the ballance weights on it, b&m sell a flexplate that has a bit missing out of it to ballance the motor insted of the weights on the converter.

[Perry S (Spokane)]

As I said, my engine is a 78. So cast crank no matter what. I am sure of that. What I don't know is if the mass of a counter balance weight I need. Does the 440 take the same size weight as a 400. Some TC's have small weights, some medium, some big. This is a '78 torque converter, so it has one large weight, not the two with a drain plug. They call it a butterfly weight. Thanks for the replys though and let me know if there are different size weights for the 440 vs the 400

[Dave-R (Roppa440)]

I understand now.

I don't think engines were perfectly balanced by the factory anyway. If you wanted perfectly balanced you always had to have this done professionally. My 440 was externally balanced because of the heavy six-pack rods. Somewhere along the line before I bought the car the convertor was replaced with one without the weights. I never noticed! A V8 is naturally quite a smooth engine anyway. Most mopar vibrations are in the drivetain.

I would just go ahead and use it. Get it balanced if you ever change pistons.