Read thru the reviews on the E-Trailer site. There are some good install pictures and suggestions.
Some are not specific to the H3 so you have to watch for that.
I noted that the bags are rolled down when you get them over the lower base. Pull them out full length when you are placing them to determine the angle to mount the brace.
Yes, you do have to drill holes. They suggest at least three. I see I could have put a couple more but have not. I drilled pilot holes and used the self tapping screws they sent.
Be sure and line it up per the instructions so there is no binding. We put about 5 pounds in them to help hold them in position.
If you have any more questions I will try to answer them.
I am very pleased with the outcome.
I have found that about 12 lbs all the time improves my ride.
I do have lots of extras on the H3 all the time so the springs were compressed more than most stock H3's.
Be careful airing them up. There is not much volume in them so a short blast gets you a lot of pressure. I found giving them a snort and use a bleed down air gauge to get to what you want helps.
It also suggests airing them down when lifting to full droop. Not sure yet how that may be affected when wheeling but I don't plan on having much more than 15 lbs offroad so I have good articulation, depending on the load I have.
It corners flatter and does not lift the front end too much under full acceleration.
My extended travel in the front lends itself to lift more than some also.
We installed mine on a car lift so the suspension was fully drooped.
I noticed after I let it down the ubolts were loose.
Apparently while the suspension was hanging the leaves spread some so when the suspension was on the ground that gave some slack to the u-bolts.
I too pull an enclosed trailer and it is loaded to the max. 3500 lbs. I usually pull it with my 3/4 ton Dodge Cummins, but this will allow me to pull it with the H3 without sagging.
This was shot when the Alpha was very new and springs were stiffer and I did not have all the extra weight bolted on.
Now with 75,000 miles and lots of spring flexing it was getting to where it did not pull well.