I have not heard much about air shocks in a long time. I'm thinking of putting one or
another brand in the rear of my truck to assist in towing a rented loaded 12'x16' uhaul
brand trailer 1800 miles. If possible, i'd like to fill up the truck bed also. I do not
expect to do much other towing, and this is the first time I'll have towed anything.

The trailer weighs 1800 lbs and has max load of 2600lbs, and has "automatic
hydraulic surge brakes"

Truck: 1999 silverado 1500 2wd , ext cab, manual 5spd , 4.3L V6 with a 5000 step
bumper. Some of the vin derived codes are:

GU6 - AXLE REAR 3.42 RATIO
JC5 - BRAKE VAC POWER, 4 WHL DISC, 7,200 LBS
L35 - ENGINE GAS, 6 CYL, 4.3L, CPI, V6, 90 DEG, HO
MG5 - TRANSMISSION MAN 5 SPD, GETRAG, 84MM, 4.00 1ST, O/D
Q4B - GVW RATING 6,200 LBS

The Chevy owners manual says the 3.42 axel ratio and manual transmission allow
a max trailer weight of 4000 lbs, assuming no cargo in the truck and one passenger.

The P245/75R16 109S M+S Destination LE tires are all fairly new (8k).
Side walls say max load 2271lbs at max cold pressure of 44psi. According to
Tirerack.com the max load needs to be reduced by 9% since they are on a truck,
so the 9% reduced 4 tire total is 8266lbs

 

I guess the deal with adjustable air shocks is that they allow more weight to placed on the rear axle without bottoming out the leaf springs. But they do not address the issue of load distribution between front and rear axles. Doesn't this lead to a relatively under-weighted front end and therefore poor handling? particular at highway speeds?

 

I ended up buying a set of coil 'helper springs' for about $40. They attached with muffler-style u-clamps. They worked fine for the trip, and most winters I put them on when I start carrying around sand bags for snow traction.