Thread: 4T65E-HD with 3.05 FDR?

That is correct, the 3.29 is the final drive / differential ratio. The 2.93 is the Overall ratio between the sprocket ratio and the diff ratio. An HD transmission has a 37 tooth drive / 37 tooth driven sprocket combo which gives you a 1.121 overdrive from the sprocket ratio. 3.29/1.121 = 2.93 which is your overall ratio. The non HD transmission with the 3.29 diff have a 35 drive / 35 driven sprocket setup which is a 1.00 ratio and gives you the true 3.29 overall ratio.

To throw it out there, the Impala L36s came with 3.05FDR, but not as an HD.