[hotrodart]

I have a 400+ HP motor in my '40 coupe with only one rebuild in 40 years on the 3-speed Ford trans.....same gear set ar your '39. Never pushed it hard and it held up well. But......in high school I had a 296 inch flathead in front of a '39 trans.......had to replace the box every week......teenage driving habits!!


So.....depends on how you drive it......