Buick 350 to Chevy 350

[danabike]

Hi all! I'm new here, so if I'm doing something wrong, let me know please! I have a 69 LeSabre with a Buick 350 that I would like to swap out for a 74 Chevy 350 engine. Is there anyone out there that has done this that would be willing to offer their insight? I'm concerned that the motor mounts are different and or located differently, as well as the fact that the chevy is bolted to a 3 speed tranny, whereas my car has a TH-400. Does anyone know of a bulletin board or chat room that might help? I'm thinking that this should be a piece of cake, but that's usually my first mistake. LOL Any tricks and advice would be appreciated!

[LeSabre97mint]

Originally Posted by danabike

Hi all! I'm new here, so if I'm doing something wrong, let me know please! I have a 69 LeSabre with a Buick 350 that I would like to swap out for a 74 Chevy 350 engine. Is there anyone out there that has done this that would be willing to offer their insight? I'm concerned that the motor mounts are different and or located differently, as well as the fact that the chevy is bolted to a 3 speed tranny, whereas my car has a TH-400. Does anyone know of a bulletin board or chat room that might help? I'm thinking that this should be a piece of cake, but that's usually my first mistake. LOL Any tricks and advice would be appreciated!

Do you have both engines? Take a look, open the hood, measure.

What's wrong with the 69 engine?

Dan

[sturdei]

The engine mounts should be the same, but the transmission bolt pattern may be different. A few Buick transmissions came with a dual bolt pattern, one for buick engines and one for chevy engines. Not so sure about the flexplate. You'll need to check that out, but it your transmission has more bolt holes than are currently being used, you'll have no problem dropping the chevy engine in place. Good luck!

[elsolo]

Different motor mounts for sure, and the motor mount pedestals are different. You might be able to swap the pedestals for chevy ones without too much fabricating.

The tranny most likely will not bolt up. You can use an adapter plate or just go with a chevy pattern TH. I think the yoke on the tranny is different between chevy/BOP, I know the U-joints are different sizes but they make a conversion joint. You said the chevy was married to a 3-speed, is that a 3 speed manual? If it is then you'll need a flexplate and torque converter too, they are different.

The exhaust manifolds are obviously different.

I have to ask WHY?
350 for a 350?
If you had a bitchin big block sure, but to swap a presumably stock chevy 350 isn't worth the effort or cost.

The Buick 350 is lighter than the chevy 350 anyhow.

[sturdei]

D'oh! I was thinking of the '71 Pontiac LeMans we played in the destruction derby with! My bad.