1947 Buick Motor Swap

I have a 1947 Buick Special Series 40 Sedanette that needs a total rebuild. Would anyone know if I can swap the 1947 Buick straight 8 248 with manual trans with a 1952 263 with dynoflow trans. I know the motor mounts on the 52 are side mounts and the 47 is a front mount but I believe the front plate can be swapped to the 52. I was wondering about the drive shaft and trans mounts. Will I need to make any major modifications.
Pete

 

Pete, you have to swap the torque tube too cause the length of the manual gearbox and the Dynaflow is not the same.

 

I did the same swap years ago, except I used the 47 trans. Everything fit just fine except the trans wouldn't fit because the crank has no pilot hole for the the Dynaflow trans. Swapped cranks and it was a go. Like Orn said, you will, probably have to modify the torque tube or get a 48 Dynaflow tube and shaft.

 

Pete, use the 263. Swap the 248's front plate with motor mounts onto the 263. You may have to drill an extra hole in the old plate to match the 263 coolant p***ages. Otherwise the plates are very similar. If the 263 was equipped with a Dynaflow that's no problem. Remove the block to Dynaflow adapter off the 263. Install your 248 bellhousing (with integral rear motor mount bosses) on the 263. Install a 263 flywheel, clutch, et al on the 263. You may have to enlarge the hole in the flywheel to mate with the dynaflow crank. You will need an adapter inserted in the Dynaflow crank to fit a pilot bearing for your 3 speed. I haven't tried a 248 flywheel on a 263 so am not sure of its bolt pattern and/or balance issues. Bolt up your 3 speed and go zooming. If you have low gears in your diff, drop in a pumpkin w/3.36, 3.41, or 3.60 (3.56) gears robbed from any Buick rear axle up to 1955. While you are at it install Roadmaster front and rear brakes on your car as well. But that's a different story. John

 

Thanks for the info guys. I was able to get the front mounting plate off the 47 motor today but destroyed the harmonic balancer. I'm going to have to be a lot more careful taking the front off of the 52 motor. The 52 already has the flywheel on it so I'm half way there.
Thanks again for the information and ill let you know how I make out.
Pete

 

Pete, you asked about replacing a 3 speed equipped 248 with a dynaflow equipped 263. If your 263 had a dynaflow behind it, there's a flexplate there, not a flywheel. There is no surface to mount a clutch on a flexplate. I used a puller with 3 claws to break my balancer loose. Once it's loose it should wiggle on off. John