bags versus helpers?

[aggiedave98]

I'm going to be doing a few things to my '89 suburban 1/2ton 2wd in case nobody has read yet...

I'm doing a 3" suspension lift w/ blocks in the back (versus lift springs because of ride). I'm going to need to pull a 3- 30foot heavy trailer about once a week for only about 2 miles. I'm going to upgrade to a class IV hitch.

I'm replacing my leaf springs and will probably get a little stiffer. But, should I go for adding a helper spring that only kicks in w/ load or go w/ air bags? If air bags, how easy are they to fill up? Should I install the one to fill from inside the truck?