Originally Posted by jwfirebird
i never heard about using the same ones. i guess it depends how good the original design is. i have been using stock 350 rubber engine mounts for about 10-15 years, when ever i swapped it to the 305 that was in there before the 350, that was all they had at the parts store at the time. but i went with the poly trans mount for a th400 because they had it and its a member of the suspension on the f-bodies. the stock rubber engine mounts have seen alot of track passes, i thought they would give me a problem but not so far.
I had a 86 firebird with a TPI 350 and a 700r4, I know what your talking about with the trans mount, the torque bar from the rear end does make a big pull on the back of the trans. I put like 4 mounts in mine in 2 years. When 2nd gear would hit hard Bang! the trans is hitting the floor pan if the car.