4T65E-HD to 4T65E swap?
 

I have a 2005 Impala with a 4T65E-HD 3:29 ratio. Will A 2005 Impala 4T65E 3:29 ratio fit and work right with no modifications?
Thanks

Basically the same transmission. The diff and diff cover are the only differences.

The HD 4T65E was never optioned with a 3.29 to my knowledge and all the reference material that I have available. If your car is not supercharged the transmission can be a 3.29 non-HD.

The main differences to keep in mind with an HD vs non-HD transmission are that the non-HD had to potential of 2-3 different gear ratios, while the HD only came from the factory in one ratio 2.93. And that the passenger axle in the HD trans is shorter to accomodate the larger differential. Therefore if swapping between an HD and non-HD, the axle needs to be changed as well.