Engine Vibration

[32piro]

I have a 1969 chevy 350 hooked to a t56 transmission and I am getting a vibration from 3500 rpms up in neutral . I took the trans out and tried it out and it is not vibrating when I rev it up to 5000. Could it not be that I am not feeling it because the engine is mounted as solid without the trans??

Angelo

[jerry clayton]

do you run solid mounts?????

with the trans out do you leave the clutch attacked to flywheel???

Do you have pilot bearing/bushing???

Are you revving it with the clutch down??? or up??? wheels turning???

[32piro]

Rubber mounts, with the pressure plate on and off,and I am running a pilot bushing. when i first took the trans out I ran it without the pressure plate and it didnt vibrate so I figured that was it, but i mounted back on the flywheel in the same spot to see if would vibrate but it didnt give me the vibration.So now I am scratching my head .

[Itoldyouso]

Give us some history. Have you run this motor previously? Any shake then? Did you just rebuild it or make other changes?

Don

[32piro]

I did run the motor before I bought it but I did rev it up that high cause I knew that I was going to rebuild it . It is a stock rebuild except for a rough idling cam(comp cams 262). Other then the vibration it runs good.