First of all, get your car on a hoist if you can, OR jack it up and
put some safety blocks under it so you can get under it and see
if the drive shaft you have is has the right front on it that will fit
onto the splined shaft at the rear of your trans.
Then, if it fits onto the shaft, you should pull it out about one
inch, or even up to one and a half inch, as that is about how
much free play you want there.
Then, with the right free play at the front, lift the rear of the
drive shaft up to see if it is going to be the right length to
mate up to the rear end yoke.
If it is too long, OR too short, then you will need a different
drive shaft. If it seems to be the correct length, then you
just need to see if NAPA has, or can get you a u-joint that
will fit.
Take a picture of the picture in post # 3 above, and bring
that picture with you to the NAPA store. Maybe they can
get a u-joint with the bat wing style caps to fit 2 of the
u-joint shafts and 2 round caps it fit the other 2 u-joint
shafts.
If your drive shaft fits your ****** splined shaft and the
drive shaft seems to be the right length, then bring it
with you to NAPA and if it's your
real lucky day
maybe they can fix you up with a new joint. Good Luck
.