Hi all, I'm planning to lower my bike, for 1 or 1.5 inch. It's okay to use the lowering bolt? or replace the shock? thanks

 

Depends on what you want. The bolt will lower the bike, but at a big cost to ride quality. Some folks are OK with the more rigid ride but most aren't. The progressive 422 shocks are excellent.......they'll retain a better ride quality, are adjustable and at stock ride height, are far superior to the stock Showa shocks. Disadvantage with the 422's is their relatively high cost.....
Best ride, and adjustability on the fly, would be an air suspension, but it's 3 times the cost of the 422's.
So.........$100, $400, or $1100.......your choice.

 

I had the reverse problem-needed to raise the bike for cornering !
Please consider finding someone who has RAISED a Deluxe and use the longer shocks from the Deluxe. You may be able to trade even up and the Deluxe shocks,being longer,will LOWER your bike.
I traded a guy with a Fatboy (had short shocks) even up for my Deluxe shocks(longer shocks) and we both were very happy.He got a lower ride and I got my bike raised !
Worth a try---anyway ! (lowers about 1" with Deluxe shocks )

 

To answer your question....yes you can use the lowering bolts. I have a 2007 fatboy and I used the lowering bolts on it and it rides just fine. It is a little stiffer because I got all the adjustment out of them that I could (lowest possible) but you are going to have to expect that with what your wanting to do. You can find the bolts pretty cheap and they are pretty easy to install, but you will most likey have to have a press of some type, I did even though the instructions said that I didnt.