what to look for? Unbalanced motor?

how can I tell if my motor is out of balance? ..its already in the car and running....

its a stroker motor? what are some signs of an unbalanced motor?

thanks!

It will shake and vibratea lot and it will be worse at some rpm.

If you were to drive an unbalanced motor for say....6 miles or so how much would that damage the bearings?

It's hard to say, but if it was built with tougher performance bearings and you were easy on the rpms, it would probably be OK.

How about we start with why you are asking this question...do you have vibration? Bought the motor used and don't know anything about it?

yeah bought the motor new...stripped it down to the short block and put what I wanted on the top end.
What I had before was a 305 and now I have the 383 storker in the car....right now it just has hooker long tubes, havent gotten my exhaust run yet. Im just wondering if it unbalanced or just because im used to the old motor ...or because its only got open headers?.....when I drove it, I thought the car was going to shake apart....cause it was so damn loud!....all the noise right under me.

If I have vibrations, I wouldnt know it...I guess?

Did you use the damper and flexplate from your original motor? or did the new motor come with them? Is the motor a one piece rear main seal? Are you sure that all 8 cylinders are firing?

It didnt come with a flexplate and it came with a stock GM balancer and I changed from the stock to an ATI ....how would I check to make sure all 8 are firing?

If the car has an antenna, watch it for vibrations through different rpms. A smooth running engine won't let the antenna vibrate at all. Any sort of imbalance can be seen in the antenna vibrations.

i thinking my car used to vibrated the attenna with my old 305....with this motor I put NEW motor stock motor mounts...and wouldnt a cam cause the attenna to vibrate? I remember looking at it when I cranked it up and yeah the attenna was vibrating....I may just be paranoid about thing cause its a new motor and Im wanting everything to go smoothly...after spending so much money on it.

how can I tell if all 8 cylinders are firing? cause I pulled one of my plugs and it was coverd in gas....would that be a problem or is that normal?

It indicates a misfire problem on that cylinder, at least. Do you have two plug wires reversed?

check on interaly balanced vrs external balance engines.the stock 400 crank is ext balanced.most aftermarket 400 cranks made for the 350 block are interal balance.might be worth looking into,but im by no means a stroker expert!