Why does my steering wheel vibrate and my whole surge? on 1996 Toyota Camry

My steering wheel and basically the whole front end constantly vibrates and it's quite annoying. I just put in a semi used motor about 3 weeks ago because I threw a rod in the original motor. I also changed both of my front axels because they were close to snapping off. I have new tires so it can't be the alignment or anything like that. I have no clue what it is but it bugs the crap out of me. Also, when get up to about 40-50 mph and stay at that speed, the whole does this surging thing. It feels like the front end of my car is literally pulling or jumping. Kind of the same as bumper to bumper traffic. Maybe it's something electrical? Someone please help me, I love this car and I just want a comfortable and smooth ride again. The miles on it is kind of high, 164, I don't know if that info helps. Thank you!!!!

Asked by for the 1996 Toyota Camry
Have your suspension checked and wheel balance checked.
Okay thanks so much for replying! I greatly appreciate it