Hokay, so as I approach spring im gearing for a big build that im doing on my 82 firebird, which has the th200 and 305.

ill eventually do the motor and trans but im a sound barrier and carpet away from finishing everything but my powertrain. So as i search kijiji to maybe pickup a transmission for a slow rebuild and im wondering a couple things

I live in a rural area, so all my driving is mostly highway at 55mph. so dropping a th350 will make it good for the strip but i believe i''ll be running around 3k+ rpm on highway (which most of my driving will be on)

So would it be more worth it to just beef up a 700r4, this way i'll have my cruizing rpm's, and it'll be a little easier on the motor. I''ll almost never race it, so im just saying i think it'll be worth just dropping a 700r4 in it

 

GM produced millions of TH350's for decades with no ill effects while driving. The main real advantage to an OD transmission is to bring engine rpms down during highway speeds for fuel economy. You can still drive across the country with a TH350 just as easily as any other transmission.

Everyone has been programmed into thinking that an OD transmission is the only way to drive on the highway. It's just going to cost you more for fuel on those very long trips.

 

I can't understand anyone ever wanting to go back to a TH350 once they've tried a properly-functioning 700R-4. To me it's worth any cost. I keep breaking them, but there's always a replacement for $125 at the salvage yards. The OD is necessary, but so is the low first gear, and so is the lockup converter.