Rear shocks / struts

Hello. So I knew I had the tow package but discovered this also gave me the 3.23 gears instead of the typical 2.93. Another pretty cool thing about this old 65 Cuda.

A few questions about this picture. Trying to address some suspension issues while the gas tank is out of the way. I have KYB gas adjusts bought for the rear, but now wondering if I should have bought the Monroe shock and strut assembly, or something similar. What's involved in getting these struts off and onto the new shocks? I've never messed with them before.

The new gas line - Is it in the right position or should it feed in from the other side of the shock? (should have taken some pictures)

Lastly - has anyone added the leaf spring assists to their car? The reviews I've seen online all seem good, and the upgrade is cheap and pretty easy to do.

Thanks..

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