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I'm looking on swapping out my 3 speed manual for a TH350 in my 56. It has a 283 V-8. What other items will I need besides a new shifter, change driveshaft, add kickdown linkage and change the crossmember. Someone was telling me I will need to swap out the flywheel and also remove a bearing from the rear of the engine. I have never heard of this. I have swapped out trannie's before but this will be my first changing from manual to auto. I tried to do a search but didn't find anything. Any help on this swap will be appreciated.

Thanks,

Frank

Swap out the flywheel for a flexplate. Do you have a torque converter with the the transmission, you'll need one. Bearing? Someone was probably talking about the throw-out bearing. I don't have a 56, but will you have to make the "hump" bigger on the firewall/floor board for the automatic transmission?

I'm going to be replacing the floor pans on the truck so if I need to make the hump bigger is shouldn't be a problem. How do I know which Flexplate I need? I see one's listed in Summit with 153 tooth and also 168 tooth, and then they also list internal and external balance. The transmission I'm getting is coming with a torque converter.

I think the "bearing" that was mentioned is the pilot bushing in the back of the crankshaft. The input shaft of the manual transmission goes in it. You will also need a transmission cooler if your radiator doesn't have one built in. Also, be sure to hook up the neutral switch on the shifter to prevent the engine from starting with the trans in gear (safety first).

On some early transmissions the neck of the converter extended to fit inside of the end of the crankshaft where the pilot bearing would reside. It should not be an issue on a 350TH.
A V-8 would normally use a 168 tooth flex plate. Small blocks are internally balanced. The flex plate would be balanced separately.
Since a 56 did not come with a 283 you probably have a later model engine. Something you should check is for the starter mounting boss on the engine. Your original starter mounted on the stick shift bellhousing. With the auto it needs to mount to the block. If it is an early block and is not drilled, an adaptor plate can be puchased from various aftermarket suppliers.
I have seen many of these conversions and don't know of anyone modifying the firewall or the floor pan.
Fred