Got a 4 speed transmission that I pulled out of an original 1970 340 4 speed 4 barrel 'Cuda many many moons ago.
Is there any difference between this 4 speed transmission and one from an original TA or AAR like gear ratio..etc.
Special casting marks or stampings?

Thanks.

The T/A and AAR 4 speeds were identical in appearance but had slightly different gear ratios.

IIrc the AAR/T/A's got the new synchro design and the new interlock lever side cover that went standard in 71. I also believe they had a low first gear gear set also.

As far as external marking there were none that would specify it as a T/A or AAR like on the steering gear box but the partial VIN or the part number under the VIN should be the needed clue to determine if it is an original T/A or AAR box.

That being said unless you are getting it for the numbers matching Partial VIN there is nothing special to them that wasn't used in other tranmissions. Not like the heads or blocks that had extra material in them.