Turbo350

I'm curious if the inners of a BOP th350 and a Chevy th350 are the same.
I thinking of dropping a Pont. 400 into an 86 K10. I need the BOP case of the transmission and the output shaft of the chevy tranny for the transfer case. Thanks

They should be, but not always are.
Sometimes the internal components of a th 350 were a bit different depending on the application.
For example, the th350 installed for heavier duty applications such as with a Chevy 350 engine had 6 disks in each clutch pack. The lighter duty applucation, such as a Chevy 305 or 6 cyl engine had 5 disks.

I would say remove both shafts and measure. They should be compatible.