shaking problem

[94redz28]

i recently put in new rear shocks before the weather got bad and thought they were set pretty good but when i get to about 90-100 the tranny starts to shake really bad. i figure it has to be a shock problem but i have it stored due to bad weather. i was wonderin if this was caused due to to stiff of shocks.. need advice thanks.

 

[blue87lx]

my car would vibrate at those speeds also. aluminum driveshaft solved my problem. make sure the bolts on the driveshaft are tight and also make sure the bolts on the shocks are tight and that the rubber gromets are in. if that doesnt do it get your tires balanced and make sure they have the correct pressure