[Speedbumpauto]

Should fit like any big block with minor differences, possibly, for oil pan, headers, etc. I did the traditional 496 and am switching out the th-400 for the 4L80 as we speak. Should be back on the road in a few weeks and I'll report but the physical install is done and it fits where the 400 used to with minor changes. I used a Firebird clip and set the engine back 5 inches. IMO, some set back is needed for a decent handling truck, but the install was pretty easy. The only caveat is almost nothing is interchangeable from the older BBC's, so hot rodding the thing can be somewhat pricey.