Dropped a 350 into my 85 IROC last night. Had a very tough time hooking the TH700R4 tranny to the block. The tranny was twisted about 2 inches, and I had to pry it over to mount it. The cross member looks straight, and the rear tranny mounts and bolts all looked good and were tight.
Surely this isn't supposed to be this way. What could be causing it to be twisted? Now that I have it together, is this twisting force going to cause any other problems?

 

I ran into the same thing the other weekend. Can't say for sure but it was probably the torque arm causing it. No big deal my car has been together and driving for a week now with no trouble. But I will disconnect the torque arm before doing that again. Installing the engine involved a lot of 4 letter words and took 3 times as long as it should have because of the transmission wanting to shift to passenger side

 

Glad to hear that it is a common problem. I was beginning to think that I had other problems. It definitely was a job to get the whole thing back together again. I sure wasn't planning to spend that much time doing what I expected would be an easy part of the re-install.
Is there anything else that I can look forward to having trouble with?

 

The transmission can't twist, it is made of aluminum and it will break. More than likely the trans was either not on the jack squarely or something is holding it at an angle. I just put my trans in on tuesday night and it to was tilted to one side but it was not square on the jack and it leaned to one side. FYI

 

Maybe twisted is the wrong word, but it definitely wasn't square with the engine. I checked the jack, it was straight. I then jacked only the low side to help turn the tranny back in line. Even that wasn't enough. I had to pry the tranny back down to catch the bolts.

 

I've had problems with 700R4's with my 350 .... third one has blown and now I'm putting a T5 in.... the tranny wasn't twisted when installed as you're describing at least that I could tell... but the first one blew 2nd gear after 2 weeks of driving, the second blew first gear after less than 100 miles of driving and this last one the front pump seal went after 2 short trips and a month of sitting.

The 700R4 isn't made to take the torque of a 350. When you get it lined up correctly and you finally get to drive it... baby it for a bit. See how well it handles the torque and shifting. You may want to spend the $$$ and time to put a t-5.


I have an 85 IROC-z that's in process of being restored and dropped in a 350 with edlebrock intake and holley quad and now a t-5. Also have a friend that has an 87 GTA with a 5.7 TPI that has had to get rid of his 700R4 and put in a T-56 becuase first and second gears shredded.

 

You had your trans out and the motor hanging on the mounts. It was hanging downward to the back because it had no support, and the soft, wore-out(how old...?) factory motor mounts sagged to that position. Now you jack it back up into place and the mounts aren't settled. - Yes, it's a normal thing. Just movement in the motor mounts. I've even had new mounts that held the motor slightly twisted, thus making a pry required at the length of the trans. - These cars aren't new anymore.....