The mount you can get at any parts store. I used the mount from the v8 Tr from a car equipped with a 305. I think the 350 automatic mount would work as well

As for the crossmember, junk yard, the for sale section here, ebay, third gen ranch, ect... they are still available. You just want the one piece crossover that was used on 99% of our cars. very common

 

i just bought a 89 camaro rs 305 TBI from a old lady the dash says 35,000 miles but i believe its 135,000 if it went over. I went to drag strip decided to run it stock and ran 16.66 in 1/4 mile which is slow as ****. i decided to launch the car with a a chip i bought from a programmers so he could remove VATS and smog bs and also change timing and i told him i was adding a aftermarket exhaust and headers to the the car. I decided to do a burnout and it launch hard the day after i went to strip and i heard a big clunk so i let of the gas real fast and drove the car home and looked under neath and the damn trans mount cracked. Before it was nice and solid and drove fine with no vibrations. If you got a high horsepower motor i would say get the poly or solid mount if one can be found in solid but as of now i'm getting the stock mount again for $7.00 why deal with the vibration instead of just getting the original mount unless you really need it. if you put the poly mount in you get the vibrations cause of the tail shaft angled incorrectly if it breaks again which i doubt it will i would just got buy another one and it would still be cheaper than the es mount. **** i could even buy 3 and it would be cheaper. If you ain't drag racing all the time and don't have **** loads of torque i would stay OEM unless you like vibrations in your car all the time when driving seems like common sense to me. This mount was warn out and was just ready to go anyways. JUST GET THE OEM MOUNT.

 

Lol, since the thread was bumped, I have been replacing my stock rubber mount every 2 months like clockwork due to it breaking. This on a 2.8 auto car before the turbo was put on. Worth noting I have the 2 piece crossmember with the round mounts. But the single rubber mount is always the one to break, causing a slam shift from reverse to drive, and sometimes 1st to second.

I have a feeling switching to the one piece crossmember wont change a thing. But the mounts have a lifetime warranty, so its not like I pay everytime it breaks. Just annoying to have to keep replacing it.