Thanks for the hint, here's the link to these springs:
https://wheelersoffroad.com/product/...l-spring-pair/
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copy/paste
WHEELER’S T12 REAR COIL SPRING PAIR
$215.00 $189.99
A high performance rear coil spring set from Wheeler's Off-Road and Eibach Spring. Provides approx 1.5″ of lift and a comfortable 12% increase in spring rate on the 2003-2009 4Runner and 2007-2014 FJ Cruiser. 2010+ 4Runner gets approximately 2.5″ lift. Engineered using Eibach's industry-leading coil spring technology found in SCORE, CORR, Dakar and WRC racing. These springs are cold wound, heat treated and shot-peened to ensure the highest quality. Powdercoated black.
Sold as a pair.
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Factory rear springs are: 180 lb/in
12% increase in rate means 180 * 1.12 = 201 lb/in. That's actually pretty decent for the price I have to say.
Manufactured in the USA.