I have a 1969 Olds 442 with approx 450 horse power. I want to change my transmission from a 4 speed to an automatic with dual gate shifter. Will any of the Hydro 350s handle the horse power? Which model Hydro 350 is strongest?
Is the Turbo 400 stronger. If so will it fit in my 442 without significant modification?

 

The Th400 is stronger and is what would have been in a 442 with a 455 engine.

 

If you plan to use a dual gate, you are stuck with either an aftermarket unit or a Hurst/Olds replica with the mini console. The dual gate will not fit the 67-69 factory A/T console without significant custom modifications.