I live at 9,000ft in the san Juans. I have tried many carbs. I had two mid 80s Quadrajets in my garage. I had them built by a quadrajet specialist. I put one on the Bronco and one on my 86 chevy. They are perfect. I've had both of them up to 13,200 ft. with no problems. They perform extremely well on very steep trails. I sent the carbs in, got them back in 2 weeks. These are not just rebuilt they are custom built with an added lean /rich adjustment. The cost was $140. that can vary on the condition of the carb.
PM me if you'd like information.
PM me if you'd like information.
