Has anyone done a axle swap on a late model F body. I was thinking this might be a cheaper route then a 12 bolt or 9 in. At least for a little while.

 

Not sure I understand... you have the "latest" model F-Body, unless you are thinking of the rear out of a 98-2002 LS1. But its the same weak 10-bolt.

The 3rd Gen's had the same 10-bolt rear, except it is 3" narrower and has different brake brackets, so that wouldn't be an upgrade. There are some 3rd Gens with Australian made "9-bolts" that might be slightly better, but same problem with width, brakes.

SLP had some Dana rears made for some of the 3rd Gen Firehawks, so you might be able to find one of those, but they are pretty rare.

 

I meant change the axles to like a 31 spline or 33 spline.