I know that i have seen a debate on whether to install the coupling blocks on a 01 ZR before but I would like to start it again. What is the difference when you install them? Are they adjustable like the Polaris's? Can you just buy the blocks and install them or is their a kit? They seem to make sense but they also seem to simple. I want a better trail suspension not lake running. I don't mean to say that the suspension is not good it just feels like it is missing something when you hit the studder bumps and if this fixes that then great. The rest of the suspension seems fine and I think is adjusted correctly because I rarely bottom it out (but does happen on big stuff) and I can still walk at the end of the day with out any pain. Thanks guys lets hear it.

Also how tight do you guys run the spring on the forward rear shock. Just curious? I have ordered the shop manual hopefully it will provide enough guidance on suspension.

Coupling blocks don't suit my style of riding so I removed them from my 02. However I do agree they make for a more comfortable ride in the studder bumps. It comes down to what suits you the best.
The front shock spring I normally leave in the stock position which works find for me with dial adjust.
Many have said the AC kit is superior to the aftermarket versions.