I have a 454 just recently built....after months and months. But at any rate, the engine was balanced with anticipation of pairing it with a Muncie. After so much time waiting for the engine build, I have rethought the idea of going with a manual transmission. The question I have....if I now want to run an automatic tranny, what should I expect to have to now do with my motor. I realize that it was originally balanced with the flywheel. How much time, money and effort would be needed to have the motor rebalanced with a flexplate instead of flywheel? More importantly, will I ultimately save money running an automatic instead of manual tranny.

Originally posted by Jayfrye:
I have a 454 just recently built....after months and months. But at any rate, the engine was balanced with anticipation of pairing it with a Muncie. After so much time waiting for the engine build, I have rethought the idea of going with a manual transmission. The question I have....if I now want to run an automatic tranny, what should I expect to have to now do with my motor. I realize that it was originally balanced with the flywheel. How much time, money and effort would be needed to have the motor rebalanced with a flexplate instead of flywheel? More importantly, will I ultimately save money running an automatic instead of manual tranny. =
If it was balanced properly you should have to do nothing except bolt the flexplate on the engine.
A quality shop will never remove or add weight to the damper of flywheel of an externally balanced engine.
If you want to have it checked take your flywheel & new flexplate to your friendly machinist that balanced your engine & have him match the flexplate to your flywheel.