Street box. I bought the Doug Nash almost 40 years ago. Still have the original receipt. It came with the Hemi input shaft. I wasn't able to install it for a number of years since it required a lot of fabrication. 40 years ago I didn't have the tools or the skills to handle that kind of fab work. I finally got it installed in the car about 30 years ago. There was a ton of fab work required to install that transmission. Back when I bought it nobody said anything about fab work! The magazine articles only talked about how easy it was to install in a Camaro. They left off the part about how it required extensive work to install in a Mopar!