What's in this Barracuda?

If you put it in Drive and take off from a stop at hard throttle, is it in 3rd?
I haven't tried that. To be honest I'm not keen on testing the limits of this little 7 1/4 differential. When I was cruising really slow around the neighborhood and I switched it from 2nd to D it really struggled like when you upshift from 1st to 3rd on a stick. I thought switching from 2nd to Drive on an auto, the transmission would select the proper gear.
What kind of pics? You can't see much of the engine bay or the transmission because of the headers.