* Engine Mounting: The Chevy 350 and Oldsmobile engines (like the one originally in your Cutlass) have different mounting points. This means you'll need to modify the engine mounts or fabricate new ones to accommodate the Chevy engine.
* Transmission Compatibility: The Chevy 350 uses a different transmission bellhousing than the Oldsmobile engine. This means you will likely need to replace the transmission or find an adapter plate to connect the Chevy 350 to your existing transmission.
* Exhaust System: The exhaust manifolds on the Chevy 350 are designed for a different engine bay layout, so you'll likely need to modify or replace the exhaust system to fit the new engine.
* Other Potential Issues: There may be additional clearance issues with the steering components, firewall, or other parts of the car.
In summary: While it's not impossible, it's a significant undertaking to install a Chevy 350 in a 1971 Cutlass Supreme without modifying the transmission. You would need to make substantial modifications to the engine mounts, exhaust system, and potentially the transmission to make it work.
Alternatives to consider:
* Rebuilding the Existing Oldsmobile Engine: This is often a more straightforward and cost-effective option, as you would not need to make major modifications to the car.
* Using a Different Engine: There are other engines that might be a better fit for your Cutlass, such as a Buick 350 or a 400 cubic inch Oldsmobile. These engines would likely require fewer modifications than a Chevy 350.
Before you make any decisions:
* Research Thoroughly: Gather information on the specific requirements for your Cutlass and the Chevy 350 engine.
* Consult with Experienced Mechanics: Get professional advice from experienced mechanics to determine the feasibility and complexity of the swap.
Ultimately, the decision is yours based on your budget, technical expertise, and desired outcome.
