No matter the condition of your 1990 Eldorado, OPGI has the Proportion Valves products you need to boost performance and get you back on the road. We currently carry eight Proportion Valves items to choose from for your 1990 Eldorado, and our Price Match Guaranteed prices range from as little as $8.99 up to $115.99. OPGI offers CPP plus two other trusted brands of Proportion Valves products for your 1990 Eldorado, to help you find quality parts you can rely on. With OPGI's 45-day return policy and four customer reviews, you can shop with the utmost confidence. Enjoy parts delivered directly to your home, or visit our sunny Southern California Showroom & Warehouse to check out our Proportion Valves items in person.