Will a 350 Chevy motor and transmission fit into a 78 Buick lesabre?

no not usually a Buick and Chevy bolt up patterns are different now im not sayin you cant you can but will take alot of fabricating so i would just leave it at no you cant

Yes!!! A lot of the Buick, Oldsmobile, and Pontiac (BOP) used transmissions from the mid 1970s thru the mid to late 1980s that were called "Dual Bolt Pattern Transmissions" and these transmissions will bolt right up to your Chevy V8,as well as the BOP V8 ENGINES. If you are unlucky enough not to have one of these transmissions an adapter is available from a number of sources and they are not very expensive. Try SUMMIT OR JEGS for purchase information.

Other than the bolt up issue be prepared to change engine mounts,Engine Flex-plate (A lot of people call it a FLYWHEEL)(that bolts the crankshaft to the Transmission Torque Converter),make exhaust system modifications as well as changes to electrical wiring, changes for fuel line routing because of different locations of the fuel pump and starter.

Although this is a great swap it is NOT A BOLT IN DEAL. I recommend that you contact either the SUMMIT or JEGS Tech Help department for more information and have all needed parts on hand before starting this project....GOOD LUCK, ......mopar392