Vibration or not, it's good that your setup doesn't rely ONLY on the bolts to carry the whole load of the motor/mid plates. Some kind of motor plate shelf/saddle/cradle/frame rail (etc) for the plates to sit on will give the mounting bolts an easier life.
Some cars, (depending on design & how they were built), might require you to install the mounting bolts while it's on the jack stands. While other cars might need to be on the ground (with weight on the suspension) before the bolt holes will line up correctly.
Are you preloading the travel limiters, or adjusting them loose so the bolts install easy? This might change how much vibration you feel in the car as well.
460 street '66 Ranchero.......................finished someday.
460 race '70 Maverick..........................finished someday.
All 'glass Top Sportsman '69 Mustang......ummm, check back when I win big playing the Texas Lotto, or online poker.
page. Some ancient & newer local race video.
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