I've got #1000 EAZ-Lift WD setup that's as old as my trailer. Got them both brand new back in 2002. The hitch head is rated for #1400 tongue and #14,000 trailer, but that does not matter really..
Towed with a 97 F150 and the current truck in my sig.
Tongue weight on the trailer is around the #650 range.
But, I also load a bunch of stuff in the bed of the truck, so they help with that too.
Anyway as far as setting up, what I did was (I don't know if it's right, wrong or whatever, but has been working fine) level the trailer and measure from the ground to the bottom of the tongue.
Assuming you have an adjustable hitch head shank, position the head so the top of the ball is the same height as your level tongue.
I tilted the hitch head as much as it would go.
Hitch up the trailer and there should be some sag. That's okay, because now you adjust the bars to bring it back up.
Latch the tongue to the hitch and start cranking up on the jack. Lift the truck up a good 2-3" after taking the tongue weight off the hitch.
Install the bars in the hitch head and assuming you have the bars with chains on them put the link that goes into the stirrup thing and lift up with the cheater bar. Do the same number of links on the other side.
Lower the trailer and see how level it is.
Too high? Try one less link. Too low? Try one more link. Tongue of the trailer still too high, might need to lower the hitch head another hole if possible.
Trial and error from there to dial it in as you haul the rig down the road going over different road conditions and all.
Took me a couple of trips to dial mine in, so just know it likely won't be perfect the first time out!
๐Good luck!
Mitch
2013 F150 XLT 4x4 SuperCab Max Tow Egoboost 3.73 gears #7700 GVWR #1920 payload. 2019 Rockwood Mini Lite 2511S.