I believe that will fix your problem. My stock afm works fine on my car but the lexus v8 afm will not work, like you said the last number is different. I believe the one you bought to replace your stock was off of a lexus v8. Some people say lexus afm works on some supra's but everywhere I read they don't recommend it. I am talking about the electronic black box. If you get the same part number as your stock afm, you should be in good shape hopefully.