Flex plate bolt pattern

[F21]

Hey guys, just put together a 77 /727 bb for a friend the converter I have for it is out of a 340 with 10” flexplate bolt pattern it’s going to be going behind a stock 383 the 383 has a 11 inch flex plate bolt pattern do they make 10” flex plate that will bolt up to the 383

 

[Professor Fate]

Big block and small block crank patterns are the same, so just find a 10" flex plate- any factory 318/340/360 10" plate should work fine.
Just make sure that the convertor is neutral balance- late '72 and all '73 340 convertors were external balance.

 

[F21]

There are no weights on the engine side of the converter

 

[Demonracer]

As long as there are no weights on the convertor and the 10" flex plate is totally round, you should be good to go.

 

[F21]

Oh, it can’t be one of those Clover shaped flex plates

 

[Demonracer]

The clover shaped plate is the OEM style. Why not spend a few dollars more and buy a good aftermarket plate, rather than something that's 50 plus years old?