rearend shudder on washboard roads

[Ck1984]

what bushings are known to be cause of rearend shudder over rough washboard roads?

the 4 cradle bushings or the 3 pumpkin bushings?
and whats best bang4buck version that wont break the bank like BMR

[CamaroCracka]

You only need diff bushings if you are drag racing. Cradle bushings are probably the single best improvement you can do on the rear suspension. I've run poly and solids and recommend solids if you don't mind the $500 price tag. Polys are a bit cheaper.

[Ck1984]

Originally Posted by CamaroCracka

You only need diff bushings if you are drag racing. Cradle bushings are probably the single best improvement you can do on the rear suspension. I've run poly and solids and recommend solids if you don't mind the $500 price tag. Polys are a bit cheaper.

ok to be clear. those THREE offset or stiffer urethane diff bushings are just for racing? what do they do exactly?

AND the FOUR cradle bushings at four corners are the ones that help suspension FEEL better on bumpy washboard type roads?
IM NOT crazy about BMR type prices for these bushings and will be fine with POLY if they help this shudder.
got a recomended pic?

how do i tell if my shocks are shot?
i thought pushing down on the vehicle was sufficient but recently found out on my classic truck that doesnt work.
=whn i pushed down on my truck, the bounce back up was slow n controlled, no bounce back at all so i figured shocks were good.
BUT i recently did other suspensionwork that involved removing lower shock mount and just for shitsngiggles i tried pushing the shock up then pulling down. Turns out my shocks pushed in rather easy and were about 3x harder to pull out and thus fooled me into thinking they were good.
Do i have to do the same with camaro shocks?

[CamaroCracka]

Diff bushings keep the nose of the diff from wanting to twist upward too much during hard acceleration.

Stiffer cradle bushings reduce or eliminate deflection of the rear cradle while cornering or under acceleration. You might find Prothane or Energy Suspension poly bushings cheaper than BMR. Solids are not much more expensive than BMR poly and are really the way to go.

Other than a physical inspection, the only way I have heard of to check shocks is jouncing the car and seeing if it cycles more than once as you mentioned.

[1JEWLDSSRS]

Here's a vid of how stock vs solid cradle bushing work. I still have stock diff bushings, but have installed solid cradle bushings.