what do you have to do to change from a 4 speed to an automatic?

I am thinking about buying a motor that was set up for a 4 speed, but I have a torque converter and auto to go with it. What has to be done to the motor to bolt on the auto? Does it have to be rebalanced with the flexplate?
Thanks

 

I was going to say, sell me the four speed parts. But maybe that's not an option.

 

Nothing has to be done to the engine. The pilot bushing can just stay in the crank, We leave them in after dyno pulls anyway. If the engine was balanced, and the flywheel was drilled otherr than stock, you can have an auto flexplate balanced to the 4 speed flywheel and leave it a that. Jim Burek

 

Thanks for the info, Jim. What if I don't have the flywheel to balance the flexplate to?

 

Well, if the engine is factory balalnced, you should have no problems just putting on an automatic flexplate. If the engine had been rebuilt and rebalanced , you could have some issues, if they removed or added a fair amount of weight to the flywheel, the only way to be correct there would be to dissaemble he entire engine and have it all rebalanced with the new flexplate. Jim Burek

 

He says that the flywheel was 0 balanced. Would this mean that I would just have to have the flexplate balanced with itself? It was a rebuild that was competition balanced, and I would like to get it as close as possible. I guess it wouldn't be that big of a deal to tear it down and rebalance it, but I would prefer not to do that.

 

m It sounds like he is saying the engine was internally balanced, meaning that the flywheel and balancer would have to have been modified to be zero balanced. If this is the case, you would need an auto flexplate that is zero balanced as well. You would definately need to verify this before proceeding, otherwise you will have major vibration problems. Jim Burek