1975 454 engine and 700R4 trans. What flexplate do I need?

[HeavyHauler]

I am wanting to run a overdrive and I have heard that the 700r4 is one of the more affordable and strong transmissions to run behind a 454 engine.

For my 1975 454 engine what flexplate will I need to buy in order to run a 700r4.

Will the 700r4 just bolt up to the 454 without some type of engine adapter plate? What size converter will I need? Anything else?

I wonder if a 4l60e would be better or a 200r4?


Anybody running any of these transmissions in their bigblock truck?

[wesmigletz]

You should be able to run the stock flex plate for your year 454. Be sure to match your torque converter bolt holes to the flexplate.

A built 700R4 will live behind a stock 454 as long as you don’t beat on it too hard or tow a lot. You may want to look into a 4L80E from an 80s-90s 454 truck, get it rebuilt with the common upgrades. You will need a controller for the 4L80E. I would stay away from a 200R4. It would take too much $$$ to build one that would live a long and happy life.

[HeavyHauler]

Originally Posted by wesmigletz

You should be able to run the stock flex plate for your year 454. Be sure to match your torque converter bolt holes to the flexplate.

A built 700R4 will live behind a stock 454 as long as you don’t beat on it too hard or tow a lot. You may want to look into a 4L80E from an 80s-90s 454 truck, get it rebuilt with the common upgrades. You will need a controller for the 4L80E. I would stay away from a 200R4. It would take too much $$$ to build one that would live a long and happy life.

Awesome and thank you! I will look into getting a 4L80E instead if it has good overdrive and is more durable.