whlte88stang

hey guys hows everyone doing? its been a while since i been on but check it out. i spun a bearing in my 86 5.0 my buddy sold me a ready to go short block which he said was an 82 and said it was a 50 oz balance. but i beg to differ because i used everything from the 86 motor on the 82 and it idles pretty damn good but when i go to take it around the block i have a horrible vibration, is it possible it can be a 28 oz balanced motor and need to change the flywheel and harmonic balancer? and how bad would the vibration be if i did use a 50 oz fly and balancer on a 28 oz engine? thanks alot guys