Well I did the same thing. Got a fd for a 1980 had lambda line to put on my 78 with no lamba line. I like to say it worked but the top fuel line connections were wrong (have you checked yours) not to mention how to plumb it. I suggest you do what I did. Sell the Lamba FD on Ebay (think I made $50 profit) and get the FD with correct number for your car.