Transmission mounting problem

[1970impalacustom]

I hope I am not the only one who has ever had this problem. I own a 1970 impala custom that I am trying to get running. I had what the previous owner told me was the original engine rebuilt. The transmission was left in the car when i removed the motor. When I Installed the new motor, I noticed that the housing for the transmission was about an inch from the engine. The only thing I could think of doing was moving the transmission forward to bolt it up. The tranny is a th-350 from what the book tells me on bolt pattern and shape of the fluid pan. The tranny mount now is about an inch from the crossmember. I am worried that my driveshaft will fly out if I get it running. Could it be possible that this is a 327 instead of a 350? Are the engine mounts differant? If anyone could shed some light on this it would mean the world to me.

[curtis73]

All chevy small blocks AND big blocks use the same engine mount points. It doesn't matter if its a 265 or a 454, it will mount in the same place.

The tranny crossmember and tranny mount are in somewhat slotted holes, so its possible that it just needs to be adjusted.

Are you using the same transmission that came out of the car? Its possible that the car came with a TH400, or one of the other tailshaft lengths of TH350 and you're having trouble. The TH350 came in 3", 9", and 12" tailshafts. The TH400 came in 4", 9", and 13" tailshafts.

Proper driveshaft yoke installation will have the yoke about 3/4" out from bottomed at ride height. Slide the yoke all the way in, then the U-joint should just clear the pinion yoke. As you slide the Ujoint in to the pinion yoke, the tranny yoke should slide back about 3/4" or so. More than an inch and I'd start questioning things.

But, in a nutshell... the difference will be with the tranny. All chevy SBC and BBC engines will mount so that the tranny flange is in the same place in the car. The distance from the front of the tranny to the tranny mount will be different depending on what tranny you're using.

Look here for more info:
http://www.hotrodders.com/forum/tran...ion-30771.html
and
http://www.maliburacing.com/auto_tranny_id.htm

[72chevelleOhio]

Originally Posted by 1970impalacustom

.. The transmission was left in the car when i removed the motor... Are the engine mounts differant? If anyone could shed some light on this it would mean the world to me.

there are different styles of factory engine mounts and a lot more aftermarket engine mounts. Did you use the mounts that came on the replacement engine or the mounts that came out of the car? I imagine the cars frame has several different mounting holes for the engine mounts. If you replaced the mounts with another style and put them in the previous mounting holes on the frame, the new mounts probably have to use a different set of holes. Or you could have gotten the wrong set of engine mounts all together.

[1970impalacustom]

Sorry for the delay.

I bought new mounts for a 350 but they would not fit, so they guy traded me for some mounts for a 327. I bolted them to the last set of holes on the frame. I think I am just going to sell this thing, I just cant find the time to get it running.