driveshaft angle

[pitjeep]

78 cj5 with 4 in tough country lift 360 auto trans dana300 t- case the rear pinion has a pretty good angle on it the front one looks about right the rear driveshaft is only about 1ft long i have some vives when running about 40 & a big vibe when i take off hard the jeep was like this when i bought it would a t-case drop cure this but that would make the front shaft drop & it looks fine now or would a d.shaft with cv joints be an option & do they make one for this set up its a model 20 rearnot sure witch way to go with this its my first lifted jeep & there are no good 4x4 shops anywhere close to me
Thanks for any help on this