I just purchased a pioneer automotive flexplate to replace my tweeked original on my 455. Can I just use this out of the box? Or does it need to be balanced to my engine? It does have the weight on it. The original went to the engine builder when he balanced the motor.
Thanks

 

Check with your engine builder and see if he modified the original flexplate when he balanced the engine. If he didn't, then you're good to go. Just bolt it on.
If he did, he should be able to match the new one to the balance of the old one.