Take the carb back. If you have a Pep Boys near, they sell rebuilts done by of all folks - Holley. I put a Holley rebuilt Qjet 7042202 on my 72 307 with Performer intake. It ran perfect out of the box. The numbers out of my 72 shop manual are as follows:
72 auto Federal qjet - 7042202, Calf. auto 7042902. Manual federal - 7042203, Manual Calf. 7042903. Those numbers are for a Chevelle. They don't show any for the Elk. I also have a 74 shop manual so I can reference those numbers. Remember that the 74's had much more stringent emmissions calibration. If you can't find a correct rebuilt you could either try to do it yourself or send the carb to someplace like the Carb Shop and let them do it. That way, you'll get yours back. Hope it helps.
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Tino #28 Gold
72 auto Federal qjet - 7042202, Calf. auto 7042902. Manual federal - 7042203, Manual Calf. 7042903. Those numbers are for a Chevelle. They don't show any for the Elk. I also have a 74 shop manual so I can reference those numbers. Remember that the 74's had much more stringent emmissions calibration. If you can't find a correct rebuilt you could either try to do it yourself or send the carb to someplace like the Carb Shop and let them do it. That way, you'll get yours back. Hope it helps.
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Tino #28 Gold