My stroker should be ready to drop in tomorrow but...I may have overlooked one thing. Am I going to need a new 400sbc flywheel or is there a way to make the old one work?

 

your choice of flywheel depends on how the engine is balanced.

 

I have a 400 balancer but the machine shop already balanced it. Would have they needed a flywheel to do so?

 

are you internal or external balance

 

I am pretty sure that the crank must be externally balanced if I needed a 400 balancer right?

 

The shop would not have needed a flywheel. They would most likely either neutral-bance it, if it was an internal balance seup; or balanced it to the stock 400 spec, if it was external balance.

It could be either; there's no way for us out here to know which parts you have.

Ask your machine shop what they did, and which flywheel to use; either a 400 flywheel, or an everything else flywheel. If they tell you that you need the "everything else" (neutral balance) kind, then you have the wrong crank damper.

 

With the 400 balancer, you definately need an external balance 153 tooth flexplate. I have one if you're interested.
email me for more info.

www.geocities.com/dzperf

 

Problem is, he says his machine shop "balanced" his motor; and he says he "has" a 400 balancer; but we don't know if those 2 things have anything to do with each other.

The one piece of the puzzle that is required here is to know whether the motor is internally or externally balanced. As we all know, a 383 can easily be built either way, and given what he posted about his particular motor, there's no way to even guess which one he has.

The machine shop should know which version he has.

I'd strongly advise that he find out what his motor really is before he starts going out and buying parts that may or may not be the right thing.

 

Not to muddy the information further but..., if he has a one piece rear seal engine then the flywheel he buys will have a weight on it and should have went the the parts to be balanced.

There are several ways they may have done it though.

If it's a one piece and they neutral balanced it he will need to removed the weight and get the flywheel balanced.

If it's a two piece rear seal crank it could have either been balanced for internal or external balancing. But, if it's been internal balanced he wouldn't need a 400 balancer.

There's really no way of knowing what he needs without more information.

FYI, mine is a one piece rear seal crank, with a 400 balancer and the newer 3" bolt hole weighted flywheel. Odd combination, but correct and it was all balanced together.

Why do I have a feeling we're going to be reading a post soon about, VIBRATION in a new engine?

 

OK guys thanks for the replies. Turns out the flywheel is balanced already with a new weight. The crank is externally balanced.