OK, here is what you need to know.
It looks like you have one of those fake receiver hitches that bolt onto the bumper. Those are dangerous in that they will fool you into thinking you can tow more than you can.
I have found trailers in the ditch still hooked to the bumper, with the truck not in sight.
Get a genuine receiver hitch, the strongest one you can put on it. Never mind what the frame is rated for, a strong hitch is not going to increase the load you tow. That is the actual limit, not the hitch.
Plus the stronger hitch will have more bolts and steel to spread the load on the frame.
Then, weigh the boat setup, and then weigh the tongue weight. If its low, move the front stop roller and the winch post forward so the boat rides a little farther forward.
Usually a little bit goes a long way here.
Now, here is the tricky part. I'm going to tell you the ideal setup, you can fudge a little bit, but not much.
If, with the tongue weight correct, the back springs go down a good amount when you hook up, then you need to go with a leveling hitch if you are going to be hauling any distance at all.
Boat trailers are not as conducive to leveling hitches as travel trailers, but its doable.
When you get the hitch and get it setup on the boat, then there are two settings that are critical.
First, park the boat and truck on a flat level area. Preferably concrete or pavement. Unhook from the boat and move forward a few inches or so. Lower the boat tongue until it is level. Use a level.
Then, adjust the hitch so that the ball is the same height as the inside of the hitch. Good quality load leveling hitches are usually height adjustable. Some are infinitely adjustable, and you can get those perfect.
Others use bolts and holes. Just get that type as close as you can.
Then, comes the other adjustment. To do it right, measure the height of the front and rear bumper to the ground without the trailer hooked up.
At this point, you are going to wish you have an electric jack on the tongue, but you can do fine with a mechanical one if its heavy duty.
Raise the trailer back up and hook it to the ball. Latch it down, then start raising the tongue with the jack.
As you do, the back end of the Blazer will come up some.
Then, hook up the two spring bars to the hitch on the truck, and hook to the hole in the chains that make them firm, but still able to latch them by hand.
Then let the jack down until it is just off the ground. Measure the distance from the front and rear bumper to the ground. The measurements will be lower, but it should be lower by the same amount front and back.
If the back is lower, jack it all up again, but a little higher and take up one chain hole.
If its higher, then drop one chain hole.
In other words, if the truck was level before hooking up the boat, then it should be level afterwards.
Never use any overload springs, air shocks, or anything else to compensate for trailer weight.
They are fine for leveling the truck without the trailer, or for hauling a heavy load, and you can use them with a trailer but not to handle the tongue weight.
In other words, level the truck with them before hooking up the trailer and then leave them alone.
Use the hitch spring bars to handle the trailer weight.
Properly setup, the leveling system will distribute the load equally between the front and rear axles.
Get the tongue weight right, distribute the load correctly, get everything level, and I suspect you will not need stabilizers.
However, if you do, then most of the leveling hitches come setup for them. Just check when you buy the hitch system and see. If they already have the hook points, its an easy add on.
Also, since its a boat, surge brakes are recommended, but electrics give you more control.
I was hauling a 30 foot travel trailer with my 250 and an idiot in a semi came by me in the other lane of a 4 lane about 30 mph faster then I was. And I was doing almost 60.
When he started past, the suction started pulling my trailer over towards his. I hit the gas and locked down on the trailer brakes with my controller.
With the truck pulling hard and the trailer braking hard, it snapped it back out straight.
There are going to be people who tell you just to add springs or other things to level the truck, and there are a lot of very intelligent people who do not understand how a trailer leveling system works.
I was one of them until I sat down and studied the system.
It actually does transfer the weight from the rear axle to the front.
All the adjustments are a pain, but until you change the boat or tow vehicle, you only have to do it once.
Mark or count the chain holes so you always know which one to use, and hook up is fast.
