Would this 4 speed fit my 1968 440 barracuda coupe?

Ya, could be "made" to fit. But so many other "drop right in" units for sale out there. Just get one that makes it easy :)
Auto to 4 speed? Z bar requires the frame bracket, or use Hydraulic...depends on the look you want.
Floor hump....you need that with 4 speed. Some headers don't allow z-bar use so Hydraulic is the only option there
I have two BBlock A bodies Factory cars..... Lots of fun ;)