Or look to see if it has a kick-down cable mounted on the carb. If equipped, it'll be on the bottom of the throttle shaft. If it has a kick-down cable, it's a turbo 350.
There was a mid-year change from throttle linkage to cable, and as such the Turbo 400 kick-down switch moved from being mounted on the carb (with throttle linkage) to being mounted under dash (throttle cable).
And now that I look at the photo on my pc instead of my phone, I'd say that's a Turbo 350. It looks to have the small speedo gear housing, and also looks to have a small tranny yoke that uses the clips on the u-joint. A Turbo 400 yoke is larger, and has the different u-joint retainers.