Your 1965, 904 has a rear pump, as well as a front, pretty tricky... you can push start it if your starter dies.
To keep that trans, you will need a hybrid TC. to marry the trans to the 360 crank.
Or you can just install a later transmission with a floor-shifter. The later trans has a slip-joint driveshaft so you would need to do something with that.
AFAIK every 904 I ever built already had a bolt-in rear sprag. But the aftermarket does offer HD versions. Personally, In your car you can't install much tire so I don't see any real advantage. However, they are pretty cheap.
