If you truly are only pulling 1000lbs, just hook it up and go. Make sure it is loaded reasonably - at 1000lbs, you just be able to still pick up the weight of the tongue, but not easily (100-200lbs).
Your 4Runner will be fine, just do it (once you get that axle seal replaced). Keep the speed at 60-ish, enjoy the right lane. On the flats you can use 4th gear, but always turn of OD up hills (and down, if you want/need engine braking).
A used OEM hitch should be easy to acquire and rust free since you are in CA. If you were in SoCal, I'd have one to sell you cheap... Get a plug-n-play trailer wiring setup from etrailer.com (less than $50) - the OEM harnesses are not reliable anymore (I've gone through two stock ones).
(~3200lbs, surge brakes)
(~2000lbs, no brakes - not suggested!)
(~4000lbs, no brakes - really not recommended!)
-Charlie
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'99 4Runner SR5 Auto -
4WD swapped
'89 Camry Alltrac LE 3S-GTE 5spd
'17 Chevy Volt Premier
'16 Honda Odyssey Elite
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